Answer:
tension is how much force is being exerted on each end of the string, whereas length is how long the string is. So assuming that the string has finite mass, then the tension on the string should increase proportionally to the string according to Newton's law f=ma.
Explanation:
Someone help me?
Isaac throws an apple straight up in the positive direction) from 15 m above the ground, reaching a
maximum height of 38 meters. Neglecting air resistance, what is the ball's velocity when it hits the
ground?
Answer:
-27.3 m/s
Explanation:
Given:
y₀ = 38 m
y = 0 m
v₀ = 0 m/s
a = -9.8 m/s²
Find: v
v² = v₀² + 2a (y − y₀)
v² = (0 m/s)² + 2 (-9.8 m/s²) (0 m − 38 m)
v = -27.3 m/s
Or, you can solve with energy.
PE = KE
mgh = ½ mv²
v² = 2gh
v = -27.3 m/s
Which of these are scientific questions? Check all that apply. How will climate change affect forests? Which planet is the prettiest? How did life on Earth begin? Why did dinosaurs go extinct? Which volcano is the most amazing?
Answer:
The scientific questions here are:
a) How will climate change affect forests
b) How did life on Earth begin
c) Why did dinosaurs go extinct
Explanation:
Scientific question are logical quantifiable questions, whose answers can be measured. A good scientific question must have answers that can be tested by a carefully designed experiment or measurement. Some qualities like "prettiest" and "amazing" cannot be tested for nor are they measurable, and hence, they do not make a testable component of good scientific question.
(I) A hiker determines the length of a lake by listening for the echo of her shout reflected by a cliff at the far end of the lake. She hears the echo 2.5 s after shouting. Estimate the length of the lake.
Answer:
425 m
Explanation:
From the question,
v = 2x/t.................... Equation 1
Where v = speed of sound in air, x = Length of the lake, t = time.
make x the subject of the equation
x = vt/2............... Equation 2
Given: t = 2.5 s
Constant: v = 340 m/s.
Substitute these values into equation 2
x = 340(2.5)/2
x = 425 m.
Hence the length of the lake is 425 m
In the school cafeteria, a trouble-making child blows a 12.0 g spitball through a 25.0 cm straw. The force (F) in Newtons, of his breath as a function of the distance along the straw (x) in meters, can be modeled as a linearly decreasing function for the first half of the straw, followed by a constant force through the rest of the straw. The force decreases by half along the first half of the straw. Assume there is negligible friction and the straw is held horizontally.
(a) Sketch a plot of the force of his breath as a function of position along the straw, labeling the force at x = 0 as F0.
(b) If the spitball begins from rest and leaves the straw with a speed of 16 m/s, how much work is done on the spitball?
(c) What is the maximum force F0, that acts on the spitball?
Answer:
A.) Find the attached file
B.) 1.536 J
C.) 123N
Explanation:
Given that the force (F) in Newtons, of his breath as a function of the distance along the straw (x) in meters, can be modeled as a linearly decreasing function for the first half of the straw,
Half of the straw = 12.5 cm
Let Force F = dependent variable
And distance x = independent variable
A.) Find the attached file for the graph.
Sinnce the force decreases by half along the first half of the straw. Assume there is negligible friction and the straw is held horizontally
B.) Given that the mass M = 12g = 12/1000 = 0.012kg
And Velocity V = 16m/s
The workdone = the kinetic energy of the split ball
WD = 1/2mv^2
Substitutes m and V into the formula
WD = 1/2 × 0.012 × 16^2
WD = 1.536 Joule
C.) The maximum force acts on the spit ball will be at maximum kinetic energy.
Since work done = force × distance
Where distance = 12.5 cm
F × S = 1/2mv^2
Substitutes all the parameters
F × 0.0125 = 1.536
Make F the subject of formula
F = 1.536/0.0125
F = 122.88 N
The maximum force F0, that acts on the spitball is therefore equal to 123 N approximately.
We have that for the Question "(a) Sketch a plot of the force of his breath as a function of position along the straw, labeling the force at x = 0 as F0.
(b) If the spitball begins from rest and leaves the straw with a speed of 16 m/s, how much work is done on the spitball?
(c) What is the maximum force F0, that acts on the spitball?"
It can be said that
a) The sketch is attachedb) The workdone = [tex]1.536J[/tex]c) Maximum force = [tex]6.4N[/tex]From the question we are told
mass of spitball = 12g through a 25.0 cm straw
Generally the equation for workdone is mathematically given as
[tex]= \frac{1}{2}mv^2 - 0\\\\= \frac{1}{2} * 12*10^{-3} * 16^2\\\\= 1.536J[/tex]
Maximum force
[tex]w = \frac{1}{2}*\frac{x_0}{2}*\frac{F_0}{2} + x_0*\frac{F_0}{2}\\\\w = \frac{5}{8}x_0F_0[/tex]
Therefore,
[tex]F_0 = \frac{8w}{5x_0}\\\\F_0 = \frac{8*1.536}{5*25*10^[-2]}\\\\F_0 = 6.4N[/tex]
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Neglecting air resistance, the distance s(t) in feet traveled by a freely falling object is given by the function s(t)=16t2, where t is time in seconds. The height of a certain tower is 840 feet. How long would it take an object to fall to the ground from the top of the building?
Answer:
t=7.25 sec
Explanation:
840=16t'2,
I REALLY NEED HELP WITH PHYSICS!! HELPPP!! I’m giving 50 points :)))
Answer:
59%
Explanation:
Data obtained from the question include the following:
Input temperature = 495 K
Output temperature = 293 K
Efficiency =?
The efficiency of the car engine can be obtained by multiplying the ratio of the output temperature to the input temperature by 100 as shown below:
Efficiency = output /input x 100
Efficiency = 293/495 x 100
Efficiency = 59.1 ≈ 59%
Therefore, the efficiency of the car engine is approximately 59%
The robot HooRU is lost in space, floating around aimlessly, and radiates heat into the depths of the cosmos at the rate of 13.5 W. HooRU's surface area is 1.51 m^2 and the emissivity of its surface is 0.209. Ignore the radiation HooRU absorbs from the cold universe. What is HooRU's temperature?
Answer:
165.73 K
Explanation:
The computation of HooRU's temperature is shown below:-
As per the stefan's law, the power radiated by black body radiations which is
[tex]P = eA\sigma T^4[/tex]
where
A indicates surface area
e indicates emissitivity
T indicates temperature
now, we will put the values in the above equation
[tex]13.5 = 0.209 \times 1.51 \times \sigma \times T^4[/tex]
After solving the above equation we will get temperature which results
= 165.73 K
Therefore for computing the HooRU's temperature we simply applied the above formula.
PLEASEEE HELP, thank you :)
Answer:
The answer is B.
Explanation:
Given that the current (Ampere) in a series circuit is same so we can ignore it. We can assume that the total voltage is 60V and all the 3 resistance are different, 20Ω, 40Ω and 60Ω. So first, we have to find the total resistance by adding :
Total resistance = 20Ω + 40Ω + 60Ω
= 120Ω
Next, we have to find out that 1Ω is equal to how many voltage by dividing :
120Ω = 60V
1Ω = 60V ÷ 120
1Ω = 0.5V
Lastly, we have to calculate the voltage at R1 so we have to multiply by 20 (R1) :
1Ω = 0.5V
20Ω = 0.5V × 20
20Ω = 10V
When you urinate, you increase pressure in your bladder to produce the flow. For an elephant, gravity does the work. An elephant urinates at a remarkable rate of 0.0060 m3 (a bit over a gallon and a half) per second. Assume that the urine exits 1.0 m below the bladder and passes through the urethra, which we can model as a tube of diameter 8.0 cm and length 1.2 m. Assume that urine has the same density as water, and that viscosity can be ignored for this flow.
1) What is the speed of the flow? It is 1.2 m/s
2) If we assume that the liquid is at rest in the bladder (a reasonable assumption) and that the pressure where the urine exits is equal to atmospheric pressure, what does Bernoulli's equation give for the pressure in the bladder? (In fact, the pressure is higher than this; other factors are at work. But you can see that no increase in bladder pressure is needed!)
Answer:
1) v = 1.19 m / s , 2) P₁ = 9.308 10⁴ Pa
Explanation:
In this exercise we will simulate the emission of urine as a fluid mechanics system
1) they indicate the urine flow rate Q = 0.0060 m³ / s, they also give the diameter of the tube 8.0 cm, they ask us the speed.
Let's use the continuity equation
Q = v A
The area of a cycling tube is
A = π r² = π d² / 4
we substitute
Q = v π d² / 4
v = 4Q / π d²
let's calculate
v = 4 0.006 / (π 0.08²)
v = 1.19 m / s
2) they ask to find the pressure in the bladder, for this we use the Bernoulli equation, where the index is for the bladder and the index 2 is for the exit point
P₁ + ½ ρ v₁² + ρ g y₁ = P₂ + ½ ρ v₂² + ρ g y₂
in the exercise it indicates that the outlet pressure is equal to the atmospheric pressure P₂ = 1,013 10⁵ Pa, the velocity of the liquid in the bladder is v₁ = 0 and the height difference 1.0 m
P₁ = P₂ + ½ ρ v₂² + ρ g (y₂-y₁)
let's calculate
P₁ = 1.013₁ 10⁵⁵ + ½ 1000 1.19 + 1000 9.8 (0-1)
P₁ = 1.013 105 + 595 - 9800
P₁ = 9.308 10⁴ Pa
a body weights 28N at a height of 3200km from the earth surface.What will be the gravitational force on that body if its lies on the earth surface.
Answer:
The object would weight 63 N on the Earth surface
Explanation:
We can use the general expression for the gravitational force between two objects to solve this problem, considering that in both cases, the mass of the Earth is the same. Notice as well that we know the gravitational force (weight) of the object at 3200 km from the Earth surface, which is (3200 + 6400 = 9600 km) from the center of the Earth:
[tex]F_G=G\,\frac{M_E\,m}{d^2} \\28\,\,N=G\,\frac{M_E\,m}{9600000^2}[/tex]
Now, if the body is on the surface of the Earth, its weight (w) would be:
[tex]F_G=G\,\frac{M_E\,m}{d^2} \\w=G\,\frac{M_E\,m}{6400000^2}[/tex]
Now we can divide term by term the two equations above, to cancel out common factors and end up with a simple proportion:
[tex]\frac{w}{28} =\frac{9600000^2}{6400000^2} \\\frac{w}{28} =\frac{9}{4} \\\\ \\w=\frac{9\,*\,28}{4}\,\,\,N\\w=63\,\,N \\[/tex]
What is the magnetic force on a particle that has 0.000500 C of charge and is moving at
2.50 10m/s to the right through a magnetic field that is 4.20 T and pointing away from
you? Specify both magnitude and direction in your answer.
Answer:
1.) F = 5.3×10^-3 N
2.) Positive y - direction
Explanation:
The parameters given are:
Charge q = 0.0005C
Velocity V = 2.5010 m/s
Magnetic field B = 4.2 T
Magnetic force F = BVqsinØ
F = BVq
since Ø = 90 degree
Substitute all the parameters into the formula
F = 4.2 × 2.5010 × 0.0005
Therefore, the magnetic force on a particle is F = 5.3 × 10^-3 N
2.) According to Fleming's left hand rule, the direction of the magnetic force will be perpendicular to the magnetic field which moving upward of the screen.
Answer:
it’s f=0.0005 x 2.5 x 10^5 x 4.20
F= 525 N
+ y direction (up)
Explanation:
got it right
a man with mass 81 kg lies on the floor. what is the normal force on the man?
Answer:
Forces come in pairs, so the force of gravity (9.8 N) with the mans weight (794N) on the earth is counteracted with the normal force ( the force of the earth back on the man) which is the same
Explanation:
Forces are available in pairs, so the force of gravity (nine.8 N) with the man's weight (794N) on the planet is counteracted with the everyday force ( the pressure of the earth again on the man) that's identical.
What is the gravitational force?Gravitational force is a pressure that draws any items with mass. We name the gravitational force appealing as it constantly attempts to tug loads collectively, it never pushes them apart. In reality, every item, together with you, is pulling on each other objects inside the complete universe.
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Find the net force and acceleration. 15 points. Will give brainliest!
Answer:
[tex]\boxed{F_{net} = 28.7 \ N}[/tex]
[tex]\boxed{a = 2.1 \ m/s^2}[/tex]
Explanation:
Finding the net force:
Firstly , we'll find force of Friction:
[tex]F_{k} = (micro)_{k}mg[/tex]
Where [tex](micro)_{k}[/tex] is the coefficient of friction and m = 13.6 kg
[tex]F_{k} = (0.16)(13.6)(9.8)\\[/tex]
[tex]F_{k} = 21.32 \ N[/tex]
Now, Finding the net force:
[tex]F_{net} = F - F_{k}\\F_{net} = 50 - 21.32\\[/tex]
[tex]F_{net} = 28.7 \ N[/tex]
Finding Acceleration:
[tex]a = \frac{F_{net}}{m}[/tex]
[tex]a = \frac{28.7}{13.6}[/tex]
[tex]a = 2.1 \ m/s^2[/tex]
Sally is concerned about the X-ray images her dentist plans to take of her teeth. She has read that X-rays can cause tissue effects, such as skin reddening and hair loss. Which statement would best inform Sally of the level of risk
Answer:
B. The dentist uses X-ray radiography, which takes too short a time to cause those problems.
Explanation:
The statement B would best inform Sally of the level of risk. The dentist uses X-ray radiography, which takes too short a time to cause those problems and risk.
What is X-ray imaging?X-ray imaging provides images of human internal organs. The photos depict your body parts in various colors of black and white.
Because various tissues absorb varying quantities of radiation, this is the case. Because calcium absorbs the most x-rays, bones appear white.
When X-ray radiation passes into our bodies, it damages molecular structures and may cause injury.
Human cells are damaged by extremely high doses of radiation, as indicated by skin burns, hair loss, and an increased risk of cancer.
Sally is concerned about the X-ray images her dentist plans to take of her teeth. She has read that X-rays can cause tissue effects, such as skin reddening and hair loss.
The statement B would best inform Sally about the level of risk. The dentist uses X-ray radiography, which takes too short a time to cause those problems and risk.
Hence, statement B would best inform Sally about the level of risk.
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Ionizing radiation is radiation of sufficient energy to produce charged atoms. All of these describe ionizing radiation. is radiation of sufficient energy to produce ions. is radiation of sufficient energy to remove electrons from atoms.
Answer:
Is radiation of sufficient energy to produce ions.
Is radiation of sufficient energy to remove electrons from atoms.
Explanation:
Ionization radiation is a radiation that travels at a high speed, and possesses sufficient speed to knock electrons off of an atom or a molecule, ionizing the atom. Ionization radiation can be made of travelling subatomic particles, or an electromagnetic wave with high energy, usually the types found at the end of the electromagnetic spectrum. Some subatomic particles that produce ionization are alpha particle, beta particles, and neutron. The electromagnetic waves with ionization abilities includes Gamma rays. -rays, and high energy ultraviolet rays.
A submarine emerges 1/9 of its volume when it partially floats on the sea surface. For make it completely submerge it is necessary to allow a volume of 50,000 [L] to enter of sea water whose density is 1,026 [g / cm3]. What is the weight of the submarine?
Answer:
4,524,660 N
Explanation:
Assuming the submarine's density is uniform, 1/9th of the submarine's mass is equal to the mass of the displaced water.
m/9 = (1026 kg/m³) (50 m³)
m = 461,700 kg
mg = 4,524,660 N
Explain length and time dilation and give an example of when each is observed.
Answer:
Length contraction
A moving object traveling at a velocity approaching the speed of light will appear to be shorter or to have undergone contraction.
The proportion by which the object is observed to have contracted is given by Lorentz transformation as follows;
[tex]L = L_{0}\cdot \sqrt{1 -\dfrac{v^{2}}{c^{2}}}= \dfrac{L_{0}}{\gamma }[/tex]
Time dilation
As the relative speed of motion of an object approaches the speed of light, the clock in the frame in motion will be observed to be moving slowly or dilated in a proportion given by Lorentz transformation as follows;
[tex]T = \dfrac{T_{0}}{\sqrt{1 -\dfrac{v^{2}}{c^{2}}}}[/tex]
Explanation:
Example of length contraction example
Two square boxes of side length L which are travelling at a velocity of 0.9 × c, are going to arranged in a single box of side side length L according to length contraction Lorentz transformation, to stationary observer we have
[tex]2 \times L\cdot \sqrt{1 -\dfrac{(0.9 \cdot c)^{2}}{c^{2}}}= 0.8 \cdot L[/tex]
To the stationary observer, the 2 boxes of length L will fit side by side in the single box of length L, while to those on the space ship carrying the boxes, the size of the single box is [tex]L\cdot \sqrt{1 -\dfrac{(0.9 \cdot c)^{2}}{c^{2}}}= 0.4 \cdot L[/tex], which will not contain half of one box
Example of of time dilation example
Twin A of two twins, twin A and B went on a space journey at the speed of 0.87·c for 5 years, the number of years past for twin B when they meet again will be [tex]T = \dfrac{5}{\sqrt{1 -\dfrac{(0.87\cdot c)^{2}}{c^{2}}}} = 10.14 \ years[/tex]
Joan makes the device shown in her science class.
An illustration with a battery and ends labeled positive and negative. A wire is connected to the positive end of the battery and curls around an iron nail and connects back with the negative side of the battery.
What would happen to the magnetic field if she connects the battery in the opposite direction?
The field would stop.
The field would get stronger.
The field would reverse its poles.
The field would get weaker.
Answer:
The field would reverse its poles.
Explanation:
The current flow will reverse directions which will reverse the poles in the magnetic field created around the iron nail.
If she connects the battery in the opposite direction, the magnetic field would reverse its poles.
What is magnetic field?The magnetic field is the region of space where an object experiences the magnetic force and obtain magnetic properties.
A wire is connected to the positive end of the battery and curls around an iron nail and connects back with the negative side of the battery. This arrangement will let the current flow from the positive end of the battery towards the negative terminal of the battery.
If the battery is connected in the opposite direction, the current will flow from negative to positive terminal.
Therefore, If she connects the battery in the opposite direction, the magnetic field would reverse its poles.
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if you rub a balloon on your hair, it becomes charged, and as a result It can stick to your head without being held there. why doesn't it fall on the ground?
The balloon doesn't fall on the ground. Because the electrical field around your head disrupts Earth's gravitational field. Option A is correct.
What is the electrostatic force, and how does it work?It is a force imposed by one charge on another as a result of the field. The electrostatic force produced by one line charge on another line charge separated by r is determined by the charge potency of each charge as well as the separation distance between them.
When you brush a balloon against your hair, it charges up and can attach to your head without being kept in place.
Because the electrical field surrounding your head interrupts Earth's gravitational field, it does not fall to the earth.
Hence, option A is correct.
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250 mL 0.1 M HCl solution is mixed with 250 mL
0.2 M NaOH. The concentration of OH- in the
mixture is
Answer:
The concentration of OH⁻ in the mixture is 0.05 M
Explanation:
The reaction of neutralization between HCl and NaOH is the following:
H⁺(aq) + OH⁻(aq) ⇄ H₂O(l)
The number of moles of HCl is:
[tex] n_{HCl} = C*V = 0.1 mol/L*0.250L = 0.025 moles [/tex]
Similarly, the number of moles of NaOH is:
[tex] n_{NaOH} = C*V = 0.2 mol/L*0.250L = 0.05 moles [/tex]
Now, from the reaction of HCl and NaOH we have the following number of moles of NaOH remaining:
[tex] n_{NaOH} = 0.05 moles - 0.025 moles = 0.025 moles [/tex]
Finally, the concentration of OH⁻ in the mixture is:
[tex]C =\frac{n_{NaOH}}{V_{T}}=\frac{0.025 moles}{0.250*2 L} = 0.05 moles/L[/tex]
Therefore, the concentration of OH⁻ in the mixture is 0.05 M.
I hope it helps you!
The three-dimensional arrangement of electron groups around the central atom is called ____.
A. Election-pair repulsion
B. Electronegativity
C. Geometric design
D. Electron-group geometry
Answer:
D. Electron - group geometry
Explanation:
Just did it boom THE BANK BUSTA WINS AGAIN
SOMEONE HELP ME PLEASE!!!
a. What is the displacement of the car in the graph?
b. What distance has the car travelled?
Answer:
a. 2 m
b. 4 m
Explanation:
a. Assuming d is the position of the car, the displacement is the difference between the final position and the initial position. 3 m - 1 m = 2 m.
b. From t = 0 to t = 2.5, the car moves a distance of 3 m. From t = 2.5 to t = 4, the car moves another 1 m.
So the car moves a total distance of 4 m.
A car travels 18 km / h to the northwest. What is the speed of this car seen from another car going south at 60 km / h?
Answer:
73.8 km/h
Explanation:
The velocity of object A relative to object B is:
v = va − vb
Let's say east is +x and north is +y, and angles are measured from +x.
The velocity of the first car in the x direction is:
18 km/h cos 135° = -9√2 km/h
The velocity of the first car in the y direction is:
18 km/h sin 135° = 9√2 km/h
The velocity of the second car in the x direction is:
60 km/h cos 270° = 0 km/h
The velocity of the second car in the y direction is:
60 km/h sin 270° = -60 km/h
The relative velocity in the x direction is:
vₓ = -9√2 km/h − 0 km/h = -9√2 km/h ≈ -12.7 km/h
The relative velocity in the y direction is:
vᵧ = 9√2 km/h − (-60 km/h) = 9√2+60 km/h ≈ 72.7 km/h
The speed, or magnitude of the velocity, is:
v = √(vₓ² + vᵧ²)
v = √((-12.7 km/h)² + (72.7 km/h)²)
v ≈ 73.8 km/h
Newton's Law of Gravitation can be used to show that if an object weighs w pounds on the surface of the earth, then its weight at a distance x from the center of the earth is W(x)=wR2x2 (for x≥R), where R=3960 miles is the radius of the earth. Estimate the altitude at which a 120- lb pilot would weigh 119.5 lb
Answer:In other words, with w = 130, W = 129.5, what is x?
You find this by plugging in the values for w, W and R and solving for x.
Note: x is the distance from the center. You were asked for the distance from the surface (the altitude) so there's one more calculation to do when you find x.
Explanation:
A 1,383 kg purple car is driving southbound on a road and collides with a 1,827 kg orange car, that was traveling 31.87 m/s eastbound. The two cars collide and stick, sliding 14.54 meters before coming to rest. What was the initial velocity of the two-car system just after the collision? Take the coefficient of friction to be 0.463, and the acceleration due to gravity to be 9.8 m/s2. Answer to two decimal places.
Answer:
Explanation:
We shall apply work energy theorem to calculate the initial velocity just after the collision .
Their kinetic energy will be equal to work done by friction .
force of friction = μ mg , where μ is coefficient of friction , m is total mass and g is acceleration due to gravity
force = .463 x 3210 x 9.8
= 14565.05 N
work done = force x displacement
= 14565.05 x 14.54 = 211775.88 J
now applying work energy theorem
1/2 m v² = 211775.88 , m is composite mass , v is velocity just after the collision
.5 x 3210 x v² = 211775.88
v² = 131.94
v 11.48 m /s
Culture creates the context for behavior in society. true or false
Answer:
True every culture is diffrent and culture is the way to grow up, the people or things you live around, or the ways of life you follow or dress.
Explanation: The definition of culture is: means a particular set of customs, morals, codes and traditions from a specific time and place. All of that develops how a person may behave in society.
Answer:
true
Explanation:
just took the quiz
Let us treat a helicopter rotor blade as a long thin
rod, as shown in Fig. 8–49. (a) If each of the three rotor
helicopter blades is 3.75 m long and has a mass of 135 kg,
calculate the moment of inertia of the three rotor blades
about the axis of rotation. (b) How much torque must the
motor apply to bring the blades from rest up to a speed
of 6.0 rev/s in 8.0 s?
Rotor
Answer:
(a) 1900 kg m²
(b) 8950 Nm
Explanation:
(a) The moment of inertia of a rod about its end is I = ⅓mL².
For 3 rods of mass m = 135 kg and length L = 3.75 m, the total moment of inertia is:
I = 3 (⅓ (135 kg) (3.75 m)²)
I = 1900 kg m²
(b) Net torque = moment of inertia × angular acceleration
∑τ = Iα
First, find the angular acceleration.
ω₀ = 0 rad/s
ω = 6.0 rev/s (2π rad/rev) = 37.7 rad/s
t = 8.0 s
α = (37.7 rad/s − 0 rad/s) / 8.0 rad/s = 4.71 rad/s²
∑τ = Iα
∑τ = (1900 kg m²) (4.71 rad/s²)
∑τ = 8950 kg m² / s²
∑τ = 8950 Nm
Which of the following would cause the force of static friction to increase?
Answer:
Answer B) An increase in [tex]\mu_S[/tex]
Explanation:
Since we are talking about the force of static friction, due to its definition as the product between the normal force to the surface times the coefficient of static friction, the only two ways such force could increase is due to an increase in the normal force, or an increase in the coefficient of static friction [tex]\mu_S[/tex].
So the only valid answer is answer B)
Bumper car A (331 kg) moving east at 3.87 m/s hit stationary car B (208 kg). After, the car A moves .88 m/s east. What is the velocity of car B?
Answer:
Ub = 221.99m/s
Explanation:
(Ma x Ua)+(Mb x Ub) = (Ma + Mb)V
(331 x 3.87)+(208 x Ub) = (331 + 208)88
(1257.8) + (208 x Ub) = 47432
(208 x Ub) = 47432 - 1257.8
(208 x Ub) = 46174.2
Ub = 46174.2/208 = 221.99m/s
Ub = 221.99m/s
Answer:
4.75
Explanation:
M1V1 + M2V2 = M1V3 + M2V4
[(331*3.87) , 90°] + 0 = [(331*0.888) , 90°] + M2V4
M2V4 = 987.042 , 90°
divide through by M2
V4 = 4.75 m/s east
an elastic cord 61 cm long when a weight of 75N hangs from it, but 85cm when a weight of 210N hangs from it. what is the spring constant of the cord
Answer:
560 N/m
Explanation:
F = kx
75 N = k (0.61 m − L)
210 N = k (0.85 m − L)
Divide the equations:
2.8 = (0.85 − L) / (0.61 − L)
2.8 (0.61 − L) = 0.85 − L
1.708 − 2.8L = 0.85 − L
0.858 = 1.8L
L = 0.477
Plug into either equation and find k.
75 = k (0.61 − 0.477)
k = 562.5
Rounded to two significant figures, k = 560 N/m.