Question

Q1.Centripetal force is v^2/r. It is supplied by:

a. the rotation

b. some physical force, or else the object will move in a straight line

c. it is the only force if the object is moving through a gravitational field

d. none is needed if its speed is below a prescribed limit

Q2. The distance of an object from planet M is D. the gravitatiolnal force on the object is F. If the distance is decreased by 1/4, what is the force of gravity on the object?

a. 1/4

b same

c. 1/8

d. 16

Q3. A person jumps off a platform on the Earth and hits the ground at 6 m/s. On a planet 10 times as massive he does the same thing. The platform is a height so he again hits at 6 m/s. In the second case, his impulse is:

a. larger by 10

b. smaller

c. smaller by 1/10

d. the same as the first

Q4. Linear momentum is conserved in a system when:

a. no forces act within the system

b. no force acts on the system from the outside

c. only one particle in the system has a force acting on it

d. only elastic collisions are allowed

Q5. If F=GMm/R^2 is the force of gravity, why do we use weight (force) equals mg?

Q6. A satellite is orbitting the Earth. Gravity is the only force acting. Why doesnt it fall to the surface?

Q7. An object falls from a great height and hits the ground. Its mass is 100 kg and it is moving at a velocity of 20 m/s upon impact. After impact:

a. the Earth has no added velocity

b. the Earth is substantially altered in its orbit

c. the Earth feels nothing at all

d. the Earth has a small extra velocity to soncerve momentum

Q8. Two balls are thrown upward. Masses are .01 kg and 2 kg. right after they have left your hand, the magnitude of the acceleration of each ball is:

a, .01 and 2

b. 10/.01 and 2 x .01

c. 10/.01 and 2/.01

d. 10

Q9. A momentum change of 10 kg x(times) m/s is observed. A force of 1000 n has been applied. What is the time interval that force was applied?

a. 1s

b. .01 s

c. .1 s

d. 10 s

Q10. A momentum change of 10 kg x(times) m/s is observed. A force of 1 N has been applied. For how long did that force act?

a. 1s

b. .01 s

c. .1 s

d. 10 s

Q11. Why are dashboards padded?

Q12. According to the first law, an object in constant velocity:

a. has no force acting on it

b. has no net force acting on it

c. must have some force as it is moving

d. constant velocities cant be maintained

Q13. According to the second law:

a. the velocity of an object is related to the force on it

b. a change in velocity is related to the force on it

c. acceleration and force are related by the mass

d. the second and third are true

Q14. According to the third law:

a. if i push on a wall, it pushes back equally

b.if i push on a wall, it partly gives and doesnt push back as much

c. the wall pushes on me in anticipation of my push, so it doesnt move

d. i push unpossed

Answer #1

**1.Any motion in a curved path represents accelerated
motion, and requires a force directed toward the center of
curvature of the path. This force is called the centripetal force
which means "center seeking" force.**

**Hence ,answer is a.**

**4.** **law of conservation of
momentum-** It describes how when there are no external
forces, the momentum of a system doesn't change.

H**ence,answer is b.**

**5. g is the value of the factor
for earth .**

**hence,total force can be taken as mg.**

A 15.0 kg object is moving at 8.50 m/s. A constant force then
acts on the object for 2.25 seconds, bringing its final velocity to
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c. What is the momentum of the object before and after the force
acts?

1. For an object moving in uniform circular motion, does the
centripetal force do work on the object?
A.
Yes, because work is force times distance and the object is
moving from the force.
B.
No, because the force is always perpendicular to the object's
displacement.
C.
No, because the displacement of the object is zero.
D.
Yes, because the object is moving.
2. An object is moving along a straight line with a speed of v
when it hits...

a. Two ice skaters are standing at the center of a frictionless
pond. Skater 2 has twice the mass of skater 1. Skater 2 pushes on
skater 1. Which of the following is true? i. Skater 1 and skater 2
both have the same speed after the push. ii. Skater 1 has twice as
much momentum as skater 2 after the push iii. The total momentum of
the 2 skaters after the push is zero iv. None of the above....

1.What's the difference between velocity and speed?
A. Velocity has direction
B. Speed is measured in m/s
C. Speed is faster than velocity
D. There is no difference
2. Which of the following statements are true about impulse?
(Select all that apply)
A. Objects involved in collisions encounter impulses
B. The kg•m/s is equivalent to the units on impulse
C. Impulse is a force
D. The Newton is the unit for impulse
E. In a collision, the net impulse experienced...

1.The momentum of an object is not dependent on which one of
the following quantities?
a) acceleration b) inertia
c) mass
d) velocity
2.Which one of the following statements concerning the
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positive value is true?
a) The momentum of the system is increasing.
b) The momentum of the system is decreasing.
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When the velocity v of an object is very large, the magnitude
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(c) Kinetic friction on box A and kinetic friction on box B (d)
Static friction on box A and kinetic friction on...

A force is applied to 1.65 kg object moving with a speed of
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d) What function describes the...

2. A 0.768 kg object is moving with a velocity of
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Please label and show all work since I have no idea what I am
doing. Thank you

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