Answer:
1350kgm/s
Explanation:
Given parameters:
Mass of footballer = 75kg
Velocity = 18m/s
Unknown:
Momentum = ?
Solution:
The momentum of a body is the quantity of motion it posses.
It is mathematically given as:
Momentum = mass x velocity
Momentum = 75 x 18
Momentum = 1350kgm/s
The water drops fall at regular intervals from a tap 5 m above the ground. The third drop is leaving the tap at the instant the first touches the ground. How far above the ground is the second drop at that instant?
I will mark brainliest
Answer:
The second drop is 3.75 m above the ground
Explanation:
Free Fall Motion
A free-falling object falls under the sole influence of gravity without air resistance.
If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is [tex]g = 9.8 m/s^2[/tex].
The distance traveled by a dropped object is:
[tex]\displaystyle y=\frac{gt^2}{2}[/tex]
If we know the height h from which the object was dropped, we can find the time it takes fo hit the ground:
[tex]\displaystyle t=\sqrt{\frac{2y}{g}}[/tex]
When the first drop touches the ground there are two more drops in the air: the second drop still traveling, and the third drop just released from the tap.
The total time taken for the first drop to reach the ground is:
[tex]\displaystyle t_1=\sqrt{\frac{2*5}{g}}[/tex]
[tex]t_1 = 1.01\ s[/tex]
Half of this time has taken the second drop to fall:
[tex]t_2 = 1.01\ s/2=0.505\ s[/tex]
It has fallen a distance of:
[tex]\displaystyle y_2=\frac{9.8(0.505)^2}{2}[/tex]
[tex]y_2 = 1.25\ m[/tex]
Thus its height is:
h = 5 - 1.25 = 3.75
The second drop is 3.75 m above the ground
A section of a sphere has a radius of curvature of 0.72 m. If this section is painted with a reflective coating on both sides, what is the focal length of:
Answer:
The value is [tex]f = 0.36 \ m[/tex]
Explanation:
From the question we are told that
The radius of curvature is [tex]R = 0.72 \ m[/tex]
Generally the radius of curvature is mathematically represented as
[tex]R = 2f[/tex]
Here [tex]f[/tex] is the focal length hence
[tex]f = \frac{R}{2}[/tex]
=> [tex]f = \frac{0.72}{2}[/tex]
=> [tex]f = 0.36 \ m[/tex]
What is the period of an object that makes 6 revolutions a minute?
Answer:
T = 10 s
Explanation:
First, we need to find the frequency of the object as follows:
[tex]Frequency = f = \frac{Speed\ in\ rpm}{60}[/tex]
where,
Speed = Angular Speed = 6 rpm
Therefore,
[tex]f = \frac{6\ rpm}{60}\\\\f = 0.1\ Hz[/tex]
Now, for time period (T):
[tex]Time\ Period = T = \frac{1}{f}\\\\T = \frac{1}{0.1\ Hz}\\\\[/tex]
T = 10 s
The physical quantity which have both magnitude and direction is a vector?why?
Answer:
hiiiiiiiiiiiii baby.........
Mary and John are seated on a bench a distance 2 part. Suddenly, John moves closer to Mary and claims that he has been drawn by the gravitational force. Is John’s claim justifiable? Show quantitatively. (Assume the masses of John and Mary are 67 and 55 respectively, and the coefficient of static friction between John and the bench is 0.15). [4]
Answer:
no
gravitational force between them is far smaller than the frictional force between the guy and the bench
A 1.0 kg object is attached to a 0.50 m string. It is twirled in a horizontal circle above the ground at a speed of 5.0 m/s.
The direction of the acceleration at the point shown points towards which letter?
Given that,
Mass of the object, m = 1 kg
It moves in a circle of radius 0.5 m with a speed of 5 m/s
To find,
The direction of the acceleration.
Solution,
Whenever an object moves in a circular path, the only force that acts on its is centripetal force which is given by the formula as follows :
[tex]F=\dfrac{mv^2}{r}[/tex]
The centripetal acceleration acts in the direction of force. It acts along the radius of the circular path. In this figure, the direction of the acceleration is shown at point d.
Answer:
D!
Explanation:
took the test
A particular engine has a power output of 5 kW and an efficiency of 30%. If the engine expels 6464 J of thermal energy in each cycle, find the heat absorbed in each cycle. Answer in units of J.
Answer:
The heat absorbed in each cycle is 9,234.286 J
Explanation:
Given;
power output, P = 5 kW = 5,000 W
efficiency of the engine, e = 30 % = 0.3
thermal heat expelled, [tex]Q_c[/tex] = 6464 J
let the heat absorbed = [tex]Q_h[/tex]
The efficiency of the engine is given as;
[tex]e = \frac{W}{Q_h} = \frac{Q_h-Q_c}{Q_h} = \frac{Q_h}{Q_h} - \frac{Q_c}{Q_h} = 1-\frac{Q_c}{Q_h}\\\\e = 1-\frac{Q_c}{Q_h}\\\\0.3 = 1-\frac{Q_c}{Q_h}\\\\\frac{Q_c}{Q_h} = 1-0.3\\\\\frac{Q_c}{Q_h} = 0.7\\\\Q_h = \frac{Q_c}{0.7} \\\\Q_h = \frac{6464}{0.7} = 9,234.286 \ J.[/tex]
Therefore, the heat absorbed in each cycle is 9,234.286 J.
calculate the electric potential energy in a capacitor that stores 1.0x10^-10C of charge at 100.0V
1 x 10⁻¹² C are stored in the system.
The power required to move a charge in opposition to an electric field is known as electric potential energy. A charge must be moved through a stronger electric field with more energy, but it also must be moved through a weaker electric field with more energy.
Electric potential at a place in an electric field is the amount of work done to move the unit positive charge from infinity to that point, and electric potential energy is fundamentally different.
Given are the following values: Stored charge, Q= 1x 10⁻¹⁰ C Voltage, V=100 v
We are aware that the formula for a system's capacitance is C=Q/V
= 1 x 10⁻¹⁰ / 100.
=1 x 10⁻¹² C
As a result, it is the necessary remedy.
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Which measurement is used to determine if an object has balanced forces
Answer:
a spring scale
Explanation:
i think it is correct
are aliens real in 2020
Answer:
i believe that they are or there's something out there
Explanation:
:)
A train travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. Its acceleration is
velocity of the train is same so acceleration of the train is zero.
Acceleration of an object is known as change in velocity of the object. For a given interval of time.
Distance travelled by the train in first second is, d₁ = 6m
Distance travelled by the train in the 2nd second is, d₂ = 6m
Distance traveled by the train in 3rd second, d₃ = 6m
Formula for the velocity of the train.
v= d/t
where v is velocity
d is distance travelled
t is time taken
For first second velocity is
v₁ = d₁/t₁
v1 = 6/1s = 6m/s
for 2nd second velocity is
v₂= d₂/t₂
v₂ = 6/1 = 6m/s
for 3rd second velocity is
v₃ = d₃/t₃
v₃ = 6/1 = 6m/s
here we saw that the speed of train remains constant for each interval of time. So change of velocity is zero.
velocity of the train is same so acceleration of the train is zero.
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1. Why is physics sometimes called the fundamental science?
Because it explains the basics of all sciences
Because it examines the rules that govern the universe
Because it does not require experiments or the scientific method
Because it was developed before any other branch of science
Because it is the easiest branch of science to understand
Explanation:
Because it is the easiest branch of science to understand
A crow flies forward and backward. Its motion is shown on the following graph of horizontal position x vs.
time t.
What is the instantaneous velocity of the crow at t = 9 s ?
A crow flies forward and backward. Its motion is shown on the following graph of horizontal position x vs. time t.
What is the instantaneous velocity of the crow at t = 9 s?
Answer: -0.50 m/s
A crow flies forward and backward. Its motion is shown in the following graph and the instantaneous velocity of the crow at t = 9 s is -0.5 m/s.
From the figure, it shows that from t = 8sec to t = 12 sec the displacement is decreasing, so velocity will be the slope of the straight line.
The velocity is given by:
velocity = -Δx ÷ Δt
velocity = (-2) ÷ (12-8)
velocity = -2 ÷ 4
velocity = -0.5 m/s
Therefore, A crow flies forward and backward. Its motion is shown in the following graph and the instantaneous velocity of the crow at t = 9 s is -0.5 m/s.
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what are the different intensity of an earthquake
Ranking Earthquake Intensity
Magnitude Average number per year Modified Mercalli Intensity
2.0 – 2.9 >1 million I
3.0 – 3.9 about 100,000 II – III
4.0 – 4.9 about 10,000 IV – V
5.0 – 5.9 about 1,000 VI – VII
Explanation:
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5. Correct the statement : Human being
can hear sounds of frequencies upto
60000Hz.
Answer:
Humans can detect sounds in a frequency range from about 20 Hz.
A car is driving directly north on the freeway at a speed of 119 km/h and a truck is leaving the freeway driving 87.7 km/h in a direction that is 35° west of north. Assume north to be in the +y-direction and east to be in the +x-direction.
What is the magnitude of the velocity of the truck relative to the car?
What is the direction of the velocity of the truck relative to the car?
The magnitude of the velocity of the truck relative to the car is 183.9 km/h
The direction of the velocity of the truck relative to the car is 67 ⁰ north of west.
Velocity of the truck relative to the carThe velocity of the truck relative to the car is the resultant velocity of the vehicles.
The resultant velocity of the car is calculated as follows;
Vertical component of the velocityVyi = 119 km/h
Vy2 = 87.7 km/h x sin(35) = 50.3 km/h
Vy(total) = 119 km/h + 50.3 km/h = 169.3 km/h
Horizontal component of the velocityVx = -87.7 x cos(35) = -71.84 km
Resultant velocityv = √Vy² + Vx²
v = √[(169.3²) + (-71.84)²]
v = 183.9 km/h
Direction of the velocityθ = arc tan(Vy/Vx)
θ = arc tan(169.3 / -71.84)
θ = -67 ⁰
θ = 67 ⁰ north of west.
Thus, the magnitude of the velocity of the truck relative to the car is 183.9 km/h and the direction of the velocity of the truck relative to the car is 67 ⁰ north of west.
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Which type of wave can travel through enpty space? EXPLAIN.
a. Electromagnetic wave
b. Sound wave
c. Water wave
d.Seismic wave
Answer:
Electromagnetic waves carry energy.
Explanation:
The waves consist of transverse vibrations in electrical and magnetic fields, not vibrating particles.
As the angle between two concurrent forces is
decreased from 55° to 15°, the magnitude of
the resultant force
Answer:
resultant increases by factor of 1.12
Explanation:
EDITED :
Assume force = 1 for simplicity and one vector is on the x axis
at 55 degrees
horizontal components = 1 + cos 55 = 1.574
vertical component = sin 55 = .8192
resultant = 1.77
at 15 degrees
horizontal components = 1 + cos 15 = 1.966
vertical component = sin 15 = .2588
resultant = 1.98
resultant increases by 1.98 / 1.77 = 1.12 original
8. A penny on its side moving at speed v slides off the horizontal surface of a table a vertical distance y from the floor.
(a) Show that the penny lands a distance v12y/g from the base of the coffee table.
(b) If the speed is 3.5 m/s and the coffee table is 0.4 m tall, show that the distance the coin lands from the base of the table is 1.0 m. (Use g = 9.8 m/s2.)
The horizontal distance of the penny from the base of the table is v(2y/g)^1/2.
The distance the coin lands from the base of the table is 1.0 m
Time of motion of the penny
The time of motion of the penny is calculated as follows;
y = vt + ¹/₂gt²
where;
v is initial vertical velocity = 0y = ¹/₂gt²
2y = gt²
t² = 2y/g
t = √(2y/g)
Horizontal distance of the pennyThe horizontal distance of the penny is calculated as;
X = Vₓt -----(1)
where;
Vₓ is initial horizontal velocity = vSubstitute the value of "t" into equation (1)
X = v(√(2y/g)),
X = v(2y/g)^1/2, shown
Distance of the coinUse the formula above to determine the distance the coin lands from the base of the table.
X = v(√(2y/g)),
X = 3.5[√(2x0.4/9.8)]
X = 3.5(0.2857)
X = 1.0 m, shown
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A student applies an upward force of 52 N to a 5.6-kg physics textbook. Find the book’s acceleration (positive for up, negative for down).
Answer: The acceleration is roughly 9.3 m/s^2
The acceleration is positive.
=====================================================
Work Shown:
Using Newton's Second Law, we get,
F = m*a
52 = 5.6a
5.6a = 52
a = 52/5.6
a = 9.28571428571429 which is approximate
a = 9.3
I rounded to 2 significant figures because both 52 and 5.6 are to 2 sig figs.
The acceleration is positive because the student applied an upward force.
The units for the acceleration are in meters per second squared, abbreviated as m/s^2.
An acceleration of 9.3 m/s^2 means that after every second, the velocity has increased by 9.3 m/s.
A swimmer speeds up from 1.1 m/s to 3.2 m/s during the last 13.0 seconds of the race. What is the acceleration of the swimmer?
Answer:
a = 0.16 [m/s²]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f}=v_{o}+a*t\\[/tex]
where:
Vf = final velocity = 3.2 [m/s]
Vo = initial velocity = 1.1 [m/s]
t = time = 13 [s]
a = acceleration [m/s²]
Now replacing:
[tex]3.2=1.1+a*13\\2.1=13*a\\a=0.16[m/s^{2} ][/tex]
Can anyone answer me for this question
The statements that are true are
Statement 4 Both Y and Z are satellites for XStatement 6 Y is a satellite for XStatement 7 Z is a satellite for YWhat is a satellite?A satellite is a moon, planet of machine that orbits a planet or a star.
From the diagram, we see that X is a planet, Y is a planet and also a moon to X and z is amoon to Y and Z
Statement I - X is a satellite for YSince X does not orbit Y but Y orbits X.
So, the statement is false.
Statement II - Y is a satellite for ZSince Y does not orbit Z but Z orbits Y.
So, the statement is false.
Statement III - Both X and Z are satellites for YSince X does not orbit Y but Y orbits X, and Z orbits Y.
Since only Z orbits Y, then the statement is false.
Statement IV - Both Y and Z are satellites for XSince Z orbits Y and Y orbits X and invariably, Z also orbits X. So, Y and Z orbit X.
So, the statement is true
Statement V - Y is a satellite for both X and ZSince Y orbits X but Z orbits Y, Y is a satellite for X but not Z, since Z orbits Y and is a satellite for Y.
Since Y is only a satellite for X and not Z,
So, the statement is false.
Statement VI - Y is a satellite for XSince Y orbits X, so Y is a satellite for X.
So, the statement is true.
Statement VII - Z is a satellite for YSince Z orbits Y, so Z is a satellite for Y.
So, the statement is true
So, the statements that are true are
Statement 4 Both Y and Z are satellites for XStatement 6 Y is a satellite for XStatement 7 Z is a satellite for YLearn more about satellites here:
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Which describes one feature of the image formed by a convex mirror?????
Answer:
The image formed by a convex mirror will always have its smaller than the size of the object no matter what the position of the object.
Explanation:
The image formed by a convex mirror will always have its smaller than the size of the object no matter what the position of the object.
Also notice that convex mirror always makes virtual images.
Another feature of the convex mirror is that an upright image is always formed by the convex mirror.
An important mirror formula to remember which is applicable for both convex and mirrors
1/f= 1/u + 1/vHere:
'u' is an object which gets placed in front of a spherical mirror of focal
length 'f' and image 'u' is formed by the mirror.
Answer:
right side up
Explanation:
How does the movement of thermal energy differ from that of other forms of energy?
heat and thermal energy can be differentiated as is that thermal energy is not actually transferred. It is not moving, but remains part of the system's internal energy. Heat, on the other hand, is a passing energy. H. Energy transferred from a hotter system.
In summary, thermal energy is the energy hipster. As such, it cannot be converted into other types of energy. Only the difference in thermal energy can be converted/used to do work. Such processes are never 100% efficient. Every energy form that cannot be recovered.
Thermal energy transfer occurs in three ways: convection, conduction and radiation. When heat energy is transferred between adjacent molecules that are in contact with each other, it is called conduction
Thermal energy and temperature are closely related. However, temperature is the average kinetic energy of matter particles and thermal energy is the total kinetic energy of matter particles.
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What happens when light from the sun passes through any type of matter
Answer:
its it filled with energy
Answer:
The light slows down.
Explanation:
A nuclear explosion results in a mass decrease of 2.10 g. how much energy is released during this explosion?(c = 3.00 x 108 m/s)
a. 2.25 x 10^12J
b. 1.89 x 10^13J
c. 1.89 x 10^14J
d. 6.30 x 10^5J
Answer: c. 1.89 x 10^14 J
Explanation:
By Einstein's equation, we know that:
E = m*c^2
Where m is the mass-consumed in this case:
m = 2.10g
And we must rewrite this in Kg, knowing that:
1kg = 1000g
Then:
m = 2.10g = (2.10/1000) kg = 0.0021 kg
And c is the speed of light:
c = 3*10^8 m/s.
Then the energy will be:
E = 0.0021 kg*(3*10^8 m/s)^2 = 1.89*10^14 Joules.
The correct option is:
c. 1.89 x 10^14J
. Emily pushes a 38.8 kg grocery cart of groceries by exerting a 76.0 N force on the handle inclined at 40.0 degrees below the horizontal. What are:
a. The horizontal and vertical components of Emily’s force
b. The acceleration of the cart?
Answer:
a) [tex]F_{x} = 58.2 N[/tex]
[tex] F_{y} = 48.9 N [/tex]
b) a = 1.5 m/s²
Explanation:
a) The horizontal and vertical components of Emily's force can be found knowing the angle and the exerted force.
Since the handle is inclined at 40.0° below the horizontal we have:
[tex] F_{x} = |F|*cos(\theta) = 76.0 N*cos(40) = 58.2 N [/tex]
[tex] F_{y} = |F|*sin(\theta) = 76.0 N*sin(40) = 48.9 N [/tex]
b) The acceleration of the car can be calculated as follows:
[tex] F_{x} = ma [/tex]
We used the horizontal component of the force because the cart is moving in that direction.
[tex] a = \frac{F_{x}}{m} = \frac{58.2 N}{38.8 kg} = 1.5 m/s^{2} [/tex]
Hence, the acceleration of the car is 1.5 m/s².
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Which of the following is a disadvantage of hybridization? 1.offspring are genetic copies of the parent 2.offspring are stronger and larger than the parents 3.offspring have a combination of traits from both parents 4.offspring often have health problems and are sterile
Answer:
Explanation:
4 is right
A trailer truck traveling east at 38 m/s sounds a 1300 Hz horn. what is the wavelength stationary listener west?
Answer:
0.0292mExplanation:
The velocity of sound wave is expressed using the formula;
[tex]v = f \lambda[/tex] where
f is the frequency
[tex]\lambda\\[/tex] is the wavelength
Given
f = 1300Hz
v = 38m/s
Required
wavelength [tex]\lambda\\[/tex]
From the formula;
[tex]\lambda\\[/tex] = v/f
[tex]\lambda\\[/tex] = 38/1300
[tex]\lambda\\[/tex] = 0.0292m
Hence the required value of the wavelength is 0.0292m
The wavelength of a stationary listener is 0.029 m.
The given parameters;
speed of the truck's sound, v = 38 m/sfrequency of the truck's sound, f = 1300 HzThe wavelength of a stationary listener is calculated as follows;
[tex]v = f\lambda[/tex]
where;
λ is the wavelength of the sound wave
The value of the wavelength is determined as;
[tex]\lambda = \frac{v}{f} \\\\\lambda = \frac{38}{1300} \\\\\lambda = 0.029 \ m[/tex]
Thus, the wavelength of a stationary listener is 0.029 m.
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The position of a particle moving along the x-axis is
given by x=(11 + 14t-2.0f), where t is in seconds and x
is in meters. What is the average velocity during the time
interval from f = 1.0 s to t=4.0 s
The average velocity during the time interval is (V)=4m/s.
What is average velocity?Velocity is a expression of the displacement that an object or particle undergoes with respect to time. Velocity is a vector quantity. The average velocity means total distance divided by total time.
How can we calculate the average velocity?To calculate the average velocity we are using the formula,
Vₙ = (v₁+v₂)/2
Here we are known,
v₁= The position of a particle moving along the x-axis with the average velocity during the time interval from t = 1.0 s
v₂= The position of a particle moving along the same x-axis with the average velocity during the time interval from t = 4.0 s
We have to calculate, the average velocity during the time interval= Vₙ
To calculate the velocities we are using the formula,
v = dx/dt
Here, x=11+14t-2t²
v=dx/dt=14-4t
At, t=1.0s, v₁=14-4*1=10m/s
At, t=4.0s, v₂= 14-4*4=-2m/s
Now, the average velocity is,
Vₙ =(v₁+v₂)/2
Or, Vₙ =(10-2)/2
Or, Vₙ =4m/s
Thus from the above calculation we can conclude that, the average velocity during the time interval from t = 1.0 s to t=4.0 s is (V)=4m/s.
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The position of a particle moving along the x-axis is given by x = (11 + 14t – 2.0t²), where t is in seconds and x is in meters. What is the average velocity during the time interval from t = 1.0 s to t = 4.0 s