A cyclist intends to cycle up an 8 degrees hill whose vertical height is 150 m, with constant speed. If each complete revolution of the pedals moves the bike 6 m along its path, calculate the average force that must be exerted on the pedals tangent to their circular path. Neglect work done by friction and other losses. The pedals turn in a circle of diameter D = 30 cm. The total mass of the cyclist and his bike is 150 kg.
Answers
Answer: [tex]1302.25\ N[/tex]
Explanation:
Given
Inclination of hill [tex]\theta=8^{\circ}[/tex]
Each revolution moves 6 m along its path
Diameter of the circle [tex]D=30\ cm[/tex]
the total mass of the cyclist and his bike [tex]M=150\ kg[/tex]
Suppose a single pedal cyclist gain a vertical height of [tex]\Delta y[/tex]
[tex]\therefore \sin \theta =\dfrac{\Delta y}{6}\\\\\Delta y=6\sin 8^{\circ}[/tex]
Average force cause to gain in Potential energy
[tex]\therefore\ F_{avg}\cdot 2\pi r=Mg\Delta y\\\Rightarrow F_{avg}=\dfrac{150\times 9.8\times 6\sin 8^{\circ}}{2\pi\cdot 0.15}\\\\\Rightarrow F_{avg}=1302.25\ N[/tex]
Thus, the average force is [tex]1302.25\ N[/tex]
Related Questions
A laser beam is incident on two slits with a separation of 0.180 mm, and a screen is placed 5.05 m from the slits. If the bright interference fringes on the screen are separated by 1.62 cm, what is the wavelength of the laser light
Answers
Answer:
The answer is "530 nm".
Explanation:
[tex]d=0.180 \ nm=0.180 \times 10^{-3} \ m\\\\L= 5.05\ m\\\\\Delta y= 1.62\ cm= 1.62 \times 10^{-2} \ m\\\\[/tex]
Using formula:
[tex]\Delta y=\frac{\lambda L}{d}\\\\\lambda =\frac{d\Delta y}{L}\\\\[/tex]
[tex]=\frac{0.180 \times 10^{-3} \times 1.62 \times 10^{-2} }{5.05}\\\\=5.30 \times 10^{-9} \times \frac{1 \ nm}{10^{-9} \ m}\\\\=530 \ nm[/tex]
Why do nuclear power plants use fission rather than fusion to generate
electric energy?
A. Fusion requires very high pressure and temperature.
B. A problem might lead to an explosion in a fusion reactor, but not
in a fission reactor.
C. The isotope used in fission is more common than the one used
in fusion.
D. Fission produces less radioactive waste than fusion does.
Answers
Answer:
A. FUSION REQUIRES VERY HIGH PRESSURE AND TEMPERATURE
Explanation:
Fission is used in nuclear power reactors since it can be controlled, while fusion is not utilized to produce power since the reaction is not easily controlled and is expensive to create the needed conditions for a fusion reaction.
Nuclear Power Plants uses Nuclear Fission over Nuclear Fusion to generate electric energy because "Nuclear Fusion requires very high pressure and temperature".
What is Nuclear Fission?Nuclear fission is a reaction in which the nucleus of an atom splitting into two or more smaller nuclei and this process produces gamma photons and releases large amount of energy by the energetic standards of radioactive decay.
The Nuclear Fission process was discovered by Hahn, Strassman and Meitner in 1938.
What is Nuclear Fusion?Nuclear Fusion is a reaction in which two or more Atomic Nuclei are combined together to form one or more different atomic nuclei and subatomic particle.
The difference in mass between the reactants and products is manifested as either the release or the absorption of energy.
Robert Atkinson and Fritz Houtermans in 1929 measured masses of light elements to show that large amounts of energy could be used released by fusing small nuclei.
Nuclear Fusion cant be used as a source of energy for heat and electricity generation because developing technology for the required purpose is the subject of ongoing research which is at its nascent stage because to reach to Nuclear Fusion , one requires very high pressure and temperature and to reach such point in one closed area is quite a herculean task.
But Scientists are working towards Nuclear Fusion as it is more advantageous over Nuclear Fission and less pollutant.
Therefore, the correct answer will be option (A)
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an electric train moving at 5m/s accelerates to a speed of 8m/s in 20 seconds. Fine the distance travelled in meters during the period of acceleration
Answers
===================================================
Explanation:
vi = 5 and vf = 8 are the initial and final velocities respectively. The change in time is t = 20 seconds.
So,
x = 0.5*(vi + vf)*t
x = 0.5*(5+8)*20
x = 130 meters
represents the distance traveled. The first equation shown above is one of the four kinematics equations.
1. What is a node?
2. What is an antinode?
3. What is a wavelength?
Will mark brainliest if correct!!
Answers
Answer:
Node:-
A node is a point along a standing wave where the wave has minimum amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effective length of the vibrating string and thereby the note played.
Anti Node:-
An antinode is simply a point along a medium which undergoes maximum displacement above and below the rest position.
Wavelength:-
The total length of circle.
or
Wavelength can be defined as the distance between two successive crests or troughs of a wave.
After Victor returns to the house in chapters 21-continuation of Frankenstein, he looks out the window and sees the monster standing outside grinning. How does Victor react
to seeing him?
A. He invites him in to have a talk.
B. He runs outside to embrace him.
C. He draws his pistol and shoots at him.
Answers
Victor reacts when he sees him and threatens to call the police if he doesn't leave. Therefore, choice C is correct.
How does Frankenstein play out?When the court learns of Victor's residence on the Orkney Islands, Kirwin presents a compelling defense of Victor at the trial and is successful in securing Victor's release. Victor's absence from his lab in the Orkneys at the time of the murder is evidence that he did not commit the crime. Victor is taken home by Alphonse.
At the conclusion of Frankenstein, what happens to Victor?Victor Frankenstein wishes he could kill the monster he created when he dies in Frankenstein. Frankenstein is visited by the Monster. He informs Walton that he intends to kill himself and expresses regret for the murders he has committed.
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Full Question = After Victor returns to the house in chapters 21-continuation of Frankenstein, he looks out the window and sees the monster standing outside grinning. How does Victor react
to seeing him?
A. He invites him in to have a talk.
B. He draws his pistol and shoots at him.
C. He threatens to call the police if he doesn't go away.
D. He runs outside to embrace him.
change $20.7 to pence
Answers
Answer:
1487.92 Pence Sterling (GBX)
An object of mass 25kg is falling from the height h=10 m. calculate
a. The total energy of an object at h=10m.
b. Potential energy of the object when it is at h= 4m
c. Kinetic energy of the object when it is at h= 4m
d. What will be the speed of the object when it hits the ground?
Answers
Answer:
a. E = 2452.5 J = 2.45 KJ
b. P.E = 981 J = 0.98 KJ
c. K.E = 1471.5 J = 1.47 KJ
d. vf = 14 m/s
Explanation:
a.
At the highest point the total energy is equal to the potential energy of the object:
E = Potential Energy = mgh
where,
E = Total energy =?
m = mass of object = 25 kg
g = acceleration due to gravity = 9.81 m/s²
h = height = 10 m
Theerfore,
E = (25 kg)(9.81 m/s²)(10 m)
E = 2452.5 J = 2.45 KJ
b.
P.E = mgh
where,
h = 4 m
Therefore,
P.E = (25 kg)(9.81 m/s²)(4 m)
P.E = 981 J = 0.98 KJ
c.
First, we will find the velocity at 4 m by using the third equation of motion:
[tex]2gh = v_f^2-v_i^2[/tex]
where,
h = height lost = 10 m - 4 m = 6 m
vf = final speed = ?
vi = initial speed = 0 m/s
Therefore,
[tex]2(9.81\ m/s^2)(6\ m) = v_f^2-(0\ m/s)^2\\v_f = \sqrt{117.72\ m^2/s^2} \\v_f = 10.85\ m/s[/tex]
Hence, the kinetic energy will be:
[tex]K.E = \frac{1}{2} mv_f^2\\\\K.E = \frac{1}{2} (25\ kg)(10.85\ m/s)^2[/tex]
K.E = 1471.5 J = 1.47 KJ
d.
We will find the velocity at the bottom by using the third equation of motion:
[tex]2gh = v_f^2-v_i^2[/tex]
where,
h = height lost = 10 m
vf = final speed = ?
vi = initial speed = 0 m/s
Therefore,
[tex]2(9.81\ m/s^2)(10\ m) = v_f^2-(0\ m/s)^2\\v_f = \sqrt{196.2\ m^2/s^2} \\[/tex]
vf = 14 m/s
If a Current Current of strength 3A flows through aresistance of 20 om for 10 minutes,then calculate the amount of heat produced in the resistance.
Answers
Answer:
1.08 x 10^5 J
Explanation:
First, apply the formula V = IR , where V is the voltage, I is the current and R is the resistance.
R -> 20 ohm (Given)
I -> 3A (Given)
Hence, V = 3 x 20 = 60V (60 volts)
Next, apply the formula E = Pt , where E is the energy produced, P is the power and t is the time in seconds
Furthermore, since P = IV (power = current x voltage)
The formula can be re-expressed as E = VIt
t -> 10 minutes = 600 seconds (don't forget to convert time to seconds!)
Therefore, energy = (60 x 3 x 600) J
= 108000 J
= 1.08 x 10^5 J (in scientific notation)
Hea produced in the resistance = energy produced in the resistor
= 1.08 x 10^5 J
To understand the nature of electric fields and how to draw field lines In (Figure 2), what is wrong with panel B7 (Pick only those statements that apply to panel B) Electric field lines are a tool used to visualize electric foiled
Part B
In (Figure 2), what is wrong with panel B? (Fick only those statements that apply to panel B) Check all that apply.
Field liner caneot cross each other
The fold lines should be paraller becauze of the sheers symunner.
The field lnes chould spread apart as they leare the sheet to indiate mhr woakering of the field with gistance.
The field lines should always end on negative charges of at infinity.
in panel B, the field lines do end on negative charges, so this is not a problem No credit lost Try again D Submit Previous Answers
Answers
In (Figure 2), the wrong with panel B is: Field line can not cross each other the field lines should be parallel because of the sheers summoner.
What is electric field line?In general, an electric field line is a curve drawn with each point's tangent pointing in the direction of that point's net field. To designate the direction of the electric field from the two potential directions provided by a tangent to the curve, an arrow on the curve is obviously required. A field line is a space curve, or a three-dimensional curve.
The wrong with panel B is: Field line can not cross each other.
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• Calculate the magnetic field strength inside a solenoid with a radius of 2m and has 2000 loops. Furthermore, it carries a 1600 A current?
Answers
The magnetic field strength of the solenoid of radius 2 m is 2.0096 T.
What is a magnetic field?Magnetic field is the region or space around which magnetic force is felt or experienced.
To calculate the magnetic field strength inside a solenoid, we use the formula below.
Formula:
B = μni/r......................... Equation 1Where:
μ = permeability of free spacen = Number of loopsr = Radius of the solenoidB = Magnetic field strengthi = CurrentFrom the question,
Given:
μ = 4π×10⁻⁷T.m/Ai = 1600 An = 2000 loopsr = 2 mSubstitute these values into equation 1
B = (4π×10⁻⁷×1600×2000/2)B = 2.0096 THence, the magnetic field strength is 2.0096 T.
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What characteristics determine how easily two substances change temperature
Answers
Answer;
Amount of time the two substances are in contact
Area in contact between the two substances
Specific heat of the material that makes up the substances
Explanation;
The change in temperature of a substance is caused by heat energy. The change in temperature will depend on factors such as mass of the substance, the type of material it is made from, the time taken , specific heat of the material that makes the substance, and also the area of contact.
The amount of time the two substances are in contact affect the change in temperature such that if the two bodies are in contact for a longer time then a bigger change in temperature will be observed.
Specific heat capacity also determines the change in temperature that will be observed, such that a substance with a bigger specific heat capacity will record a small change in temperature.
Magnetism Assessment
Magnet A is a very weak magnet and Magnet B is a very strong magnet. They attract each other. The relative attractive force is
greater from magnet A
greater from magnet B
the same for both magnets
unable to be determined
1
2
3
4
5
6
7
8
9
Answers
Answer:
greater from magnet B to A
The relative attractive force is greater for magnet B and the magnetic force is also greater for magnet B
What is magnetic force?Magnetic force is the term used to describe the force that pulls items like iron. Magnetic force is the attraction or repellence that exists between two magnetic materials. Ferromagnetic materials include iron.
The magnetic force is strongest at the poles of the magnet and weak at the center of the magnet. The magnetic force can be either attractive or repulsive and like poles repel each other whereas unlike poles attracts.
Given data ,
Let the first magnet be = A
Let the second magnet be = B
Now , the Magnet A is a very weak magnet and Magnet B is a strong magnet
And , the magnets A and B attract each other so they are unlike magnets
Since , the magnet B is a strong magnet it will gave a relatively larger attractive force when compared to the weak magnet A
Hence , the magnet B will have greater magnetic force
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The cooler star, the most ____ it is.
a) more luminous
b) more blue
c) redder
Answers
Answer:
c. more redder
def not blue cuz thats hottest and def not luminous
Answer:
it is c... redder
Explanation:
because i just look it up on googl3
What is the answer please help help ( science)
Answers
Answer:
Number 19
10 x 7.2
72N
Explanation:
20.
1.66 x 7.2
11.9
Which is approximately
12N
In a particular crash test, an automobile of mass 1759 kg collides with a wall and bounces back off the wall. The x components of the initial and final speeds of the automobile are 12 m/s and 2.2 m/s, respectively. If the collision lasts for 0.11 s, find the magnitude of the impulse due to the collision. Answer in units of kg · m/s. Calculate the magnitude of the average force exerted on the automobile during the collision. Answer in units of N.
Answers
Based on the data provided about the collision;
the magnitude of the impulse due to the collision is 21105.8 kg.m/sthe magnitude of the average force exerted on the automobile during the collision is 191870.91 NWhat is the magnitude of the impulse due to the collision of the vehicle with the wall?The magnitude of the impulse due to the collision of the vehicle with the wall is calculated using the formula of the impulse on an object given below as follows:
Impulse = change in momentum
Change in momentum = m(v - u)
where;
m is mass
v is the final velocity
u is the initial velocity
Impulse = 1759 (12 - 22)
Impulse = 21105.8 kg.m/s
The average force on the automobile will be:
Force = impulse/time
Force = 21105.8 / 0.11
Force = 191870.91 N
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2. How can we make the percent error value as minimal as possible?
Answers
Answer:
Percent error can be reduced by improving both your accuracy and precision.
Answer:
Percent error can be reduced by improving both your accuracy and precision.
Explanation:
A force of 7.36 N acts on a(n) 2.1 kg object for 24.7 s. What is the object’s change in momentum? What is its change in velocity? Answer in units of N · s
Answers
Based on the data given:
the change in momentum of the object is 181.8 N.sthe change in velocity, Δv = 86.6 m/sWhat is the change in the momentum of a body?
The change in momentum of the object equals the impulse experienced by the object
Mathematically,
Impulse = change in momentum
Impulse = F • t
change in momentum = m • Δ v
F • t = m • Δ v
where
F is the force
t is the time the force acts
m is the mass of the object
Δv is the change in velocity
For the given values:
change in momentum of the object = 7.36 * 24.7
change in momentum = 181.8 N.s
Change in velocity, Δv = change in momentum / mass
Change in velocity, Δv = 181.8 / 2.1
Change in velocity, Δv = 86.6 m/s
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URGENT HELP!
How is it that two moving objects can have a net momentum of zero?
Answers
Answer:
because they may not actually be moving be just percieved as so
Explanation:
Answer:
i think that maybe there arent moving but there on something thats moving
Explanation:
The reliability or reproducibility of a measurement is its _____
Answers
The degree of data stability when the measurement is replicated under identical circumstances is known as reproducibility or reliability.
What exactly are repeatability and reproducibility?Reproducibility determines how an entire study an experiment can be replicated, whereas repeatability assesses the variation in data made by a single equipment or human under similar circumstances.
What makes repeatability crucial?Science needs reproducibility because it enables more in-depth investigation, and replication validates our findings. There are several investigations and experiments, which result in a wide range of variables, unforeseen, and things that are either outside your influence or you cannot guarantee.
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The second order bright line appears 0.50 cm from the center bright line when a double slit grating is used. The distance between the slits is 0.25 mm and the screen is 1.20 m from the grating. Find the wavelength of the light.
Answers
Distance of nth bright fringe from center is given by :
[tex]y = \dfrac{n\lambda D}{d}[/tex]
Here, D is distance between screen and slit.
d is distance between two slits.
Now, wavelength is written as :
[tex]\lambda = \dfrac{yd}{nD}\\\\\lambda = \dfrac{0.005\times 0.25 \times 10^{-3}}{2\times 1.2}\\\\\lambda = 5.208\times 10^{-7} m = 520.8 \ nm[/tex]
Hence, this is the required solution.
______________ is the study of motion in fluids.
Hydrodynamics
Acceleration
Aerodynamics
Resistance
Answers
Answer:
i think its Hydrodynamics
Explanation:
because hydro is fluid
What will be the final temperature of a sample of water, if 32 kJ of heat is removed to lower 836
g of water starting with an initial water temperature of 25*C?
Answers
The final temperature of a sample of water is 15.89 ⁰C.
What will be the final temperature of the sample of water?
The final temperature of the sample of water is calculated by using the formula for heat capacity of water.
Q = mcΔθ
where;
Q is the heat capacity of the water = 32 kJm is the mass of the water = 836 gc is the specific heat capacity of water = 4200 J/kgCΔθ is the change in the temperature of the water = ?Δθ = Q / mc
The change in the temperature of the sample of water is calculated as follows;
Δθ = ( 32,000 ) / ( 0.836 x 4200 )
Δθ = 9.11 ⁰C
The final temperature of the water when heat is removed is calculated as follows;
T₂ = 25 ⁰C - 9.11 ⁰C = 15.89 ⁰C
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The bellows of an adjustable camera can be extended so that the largest distance from the lens to the film is 1.45 times the focal length. If the focal length of the lens is 6.14 cm, what is the distance from the closest object that can be sharply focused on the film
Answers
Answer: 19.80 cm
Explanation:
Given
focal length [tex]f=6.14\ cm[/tex] (as focal length is positive, it is converging lens)
Image distance [tex]v=1.5f[/tex]
[tex]v=1.5\times 6.14\\v=9.21\ cm[/tex]
using lens formula
[tex]\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}[/tex]
insert values
[tex]\dfrac{1}{u}=\dfrac{1}{6.14}-\dfrac{1}{8.9}\\\\\dfrac{1}{u}=0.1628-0.1123\\\\\dfrac{1}{u}=0.0505\\\\u=19.80\ cm[/tex]
Thus, the distance of the object is 19.80 cm
Given:
Focal length, f = 6.14 cmNow,
The image distance will be:
→ [tex]v = 1.5 f[/tex]
[tex]= 1.5\times 6.14[/tex]
[tex]= 9.21 \ cm[/tex]
By using the lens formula, we get
→ [tex]\frac{1}{v} + \frac{1}{u} = \frac{1}{f}[/tex]
By putting the values, we get
→ [tex]\frac{1}{u} = \frac{1}{6.14} - \frac{1}{8.9}[/tex]
[tex]\frac{1}{u} = 0.1628-0.1123[/tex]
[tex]\frac{1}{u} = 0.0505[/tex]
[tex]u = 19.80 \ cm[/tex]
Thus the answer above is correct.
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A car is travelling at 27m/s and decelerates at a=5m/s2 for a distance of 10m. Calculate its final velocity. (Hint does deceleration imply that the acceleration is positive or negative?)
Answers
If deceleration = 5 m/s²
then acceleration = -5 m/s²
According to third law of motion,
= v² = 2as + u²
= v² = 2×-5×10 + 27²
= v² = -100 + 729
= v =√ 629
= 25.08 m/s
Millikan used tiny oil droplets and adjusted the electric field until the electric force balanced the weight of the droplet, and one of the droplets hovered in air. However, the drops are all different sizes and weights, and the amount of charge on each droplet also varies. So, the tuning of the electric field is different for droplets of different sizes, which carry different charges. Let us assume that the density of the oil Millikan used in his experiment is 800 kg m3
A. Calculate the mass (in kg) of the hovering droplet if its radius is measured to be 65 um.
B. Calculate the electric field (in V/m) required to counter the weight of the above droplet if it carries a charge q = 2e.
C. In the second trial, the hovering droplet has a mass of 10-15 kg. It carries a charge of q = 11e. calculate the electric field (in V/m) required to counter the weight of this droplet.
Answers
Answer:
A. 9.203 × 10⁻¹⁰ kg
B. 2.82 × 10¹⁰ V/m
C. 5.56 × 10³ V/m
Explanation:
A. Calculate the mass (in kg) of the hovering droplet if its radius is measured to be 65 um.
We know density, ρ = mass of oil drop, m/volume of oil drop, v
m = ρv
ρ = 800 kg/m³ and v = 4πr³/3 (ince the oil drop is a sphere) where r = radius of oil drop = 65 μm = 65 × 10⁻⁶ m.
So, m = ρv = ρ4πr³/3
= 800 kg/m³ × 4π(65 × 10⁻⁶ m)³/3
= 800 kg/m³ × 4π274625 × 10⁻¹⁸ m³/3
= 878800000π × 10⁻¹⁸ kg/3
= 2760831623.97 × 10⁻¹⁸ kg/3
= 920277207.99 × 10⁻¹⁸ kg
= 9.203 × 10⁻¹⁰ kg
B. Calculate the electric field (in V/m) required to counter the weight of the above droplet if it carries a charge q = 2e.
Since the electric force F = qE where q = charge on oil drop = 2e where e = electron charge = 1.602 × 10⁻¹⁹ C and E = electric field equals the weight of the oil drop W = mg where m = mass of oil drop = 9.203 × 10⁻¹⁰ kg and g = acceleration due to gravity = 9.8 m/s².
So, F = W
qE = mg
E = mg/q
E = mg/2e
substituting the values of the variables into the equation, we have
E = 9.203 × 10⁻¹⁰ kg × 9.8 m/s²/(2 × 1.602 × 10⁻¹⁹ C)
E = 90.1894 × 10⁻¹⁰ kg-m/s²/3.204 × 10⁻¹⁹ C
E = 28.15 × 10⁹ V/m
E = 2.815 × 10¹⁰ V/m
E ≅ 2.82 × 10¹⁰ V/m
C. In the second trial, the hovering droplet has a mass of 10-15 kg. It carries a charge of q = 11e. calculate the electric field (in V/m) required to counter the weight of this droplet.
Since F = W
qE = mg
E = mg/q
E = mg/11e
E = 10⁻¹⁵ kg × 9.8 m/s²/(11 × 1.602 × 10⁻¹⁹ C)
E = 9.8 × 10⁻¹⁵ kg-m/s²/17.622 × 10⁻¹⁹ C
E = 0.556 × 10⁴ V/m
E = 5.56 × 10³ V/m
Part A : A cylindrical water tank 10cm high and 520cm in diameter is filled with solution with a density of 0.75 g/cm^3
a) What is the water pressure on the bottom of the tank? (pressure in psi)
Show calculations
b) What is the average force on the bottom?
Answers
Answer: [tex]0.1066\ psi, 15.611\ kN[/tex]
Explanation:
Given
the height of the tank is [tex]h=10\ cm[/tex]
The diameter of the tank is [tex]d=520\ cm[/tex]
Density of solution [tex]\rho=0.75\ g/cm^3\ or\ 750\ kg/m^3[/tex]
[tex](a)[/tex] Water pressure at the bottom of the tank is
[tex]P=\rho gh\\P=750\times 9.8\times 0.1\\P=735\ Pa[/tex]
[tex]1\ Pa=0.000145038\ psi[/tex]
[tex]\Rightarrow P=735\ Pa\ or\ 0.1066\ psi[/tex]
[tex](b) \text{Average force on the bottom is the product of pressure and area of the base}[/tex]
[tex]F_{avg}=735\times \pi \cdot (\frac{520}{200})^2\\\\F_{avg}=735\times 3.142\times 6.76\\F_{avg}=15,611.34\ N\ or\ 15.611\ kN[/tex]
Someone is trying to balance a (110cm) plank with certain forces.
a) Calculate the moment of the 60N force (about O), then name its type.
b) Calculate the moment of the 30N force (about O), then name its type
c) Will the plank balance? If not, which way will it tip?
d) What extra force would be needed at (B) to balance the plank?
Answers
Answer:
a. i. 30 Nm ii. This moment is a clockwise positive moment.
b. i. 15 Nm ii, This moment is a counter-clockwise negative moment.
c. i. The plank will not balance. ii. The plank would tip up.
d. 150 N
Explanation:
a) Calculate the moment of the 60N force (about O), then name its type.
i. Calculate the moment of the 60N force (about O)
Since moment = Force × perpendicular distance from point of moment ,
M = Fd
Since F = 60 N and d = 50 cm = 0.5 m
M = 60 N × 0.5 m = 30 Nm
ii. Then name its type.
This moment is a clockwise positive moment.
b) Calculate the moment of the 30N force (about O), then name its type.
i. Calculate the moment of the 30N force (about O),
Since moment = Force × perpendicular distance from point of moment ,
M' = F'd'
Since F' = 30 N and d' = 50 cm = 0.5 m
M' = 30 N × 0.5 m = 15 Nm
ii. Then name its type.
This moment is a counter-clockwise negative moment.
c) Will the plank balance? If not, which way will it tip?
i. Will the plank balance?
The plank will balance if the net moment on it is zero
So net moment, M' = positive moment - negative moment = M - M' = 30 Nm - 15 Nm = 15 Nm
Since the net moment on the plank is M" = 15 Nm ≠ 0,the plank will not balance.
ii Which way will it tip?
The plank would tip in the direction of the greater moment since the net moment is positive. This moment tilts the plank in a clockwise direction, so the plank would tip up.
d) What extra force would be needed at (B) to balance the plank?
The extra force must balance the net moment,
So M" = F"d" where F" = force and d" = distance of force from O = 10 cm = 0.10 m
F" = M"/d"
= 15 Nm/0.10 m
= 150 N
1- A ball, M = 4 kg is released from rest (vi =0) at a height, h = 2 m above the ground. (a)
What is the kinetic energy of the ball just before it hits the ground? What is the change in the
potential energy, ΔU during this motion? (b) Find the kinetic energy of the ball at a height, y
= 1.2 m above the ground. (Take g = 10 m/s2
).
Answers
(a) The kinetic energy of the ball just before it hits the ground is 78.4 J.
(b) The kinetic energy of the ball at a height of 1.2 m is 31.36 J.
What is the kinetic energy of the ball?The kinetic energy of the ball just before it hits the ground is calculated as follows;
K.E ( bottom) = P.E (top)
P.E (top) = mgh
where;
m is the mass of the objecth is the height of the objectg is acceleration due to gravityP.E (top) = 4 x 9.8 x 2
P.E (top) = 78.4 J
The change in the potential energy of the ball during its motion is calculated as follows;
ΔU = P.Ef - P.E i
where;
P.Ef is the final potential energy at ground levelP.Ei is the initial potential energy at maximum heightΔU = 0 J - 78.4 J
ΔU = -78.4 J
The kinetic energy of the ball at a height of 1.2 m is the change in the potential energy of the ball and it is calculated as follows;
K.E = -ΔU
K.E = -mg (hf - hi)
K.E = (4 x 9.8)(2m - 1.2 m)
K.E = 31.36 J
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6.__friction acts on objects that are not moving. *
which one is the answer ? (Science)
rolling
static
sliding
Answers
Answer:
STATIC friction acts on objects that are not moving........
Explanation:
DOES THIS HELPS!!
What are the 3 Laws of Newtonian Mechanics
Answers
In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction
Answer:
(1) Every object moves in a straight line unless acted upon by a force
(2) The acceleration of an object is directly proportional to the net force exerted and inversely proportional to the object's mass.
(3) For every action, there is an equal and opposite reaction.
Explanation:
Examples of Newton's 3rd Law When you jump off a small rowing boat into water, you will push yourself forward towards the water. The same force you used to push forward will make the boat move backwards. When air rushes out of a balloon, the opposite reaction is that the balloon flies up