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.

Hence,answer is b.

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

hence,total force can be taken as mg.