**Newton's Laws : Quiz 3 Practice Questions**

1. A motorcycle of mass 100 kg travels around a flat, circular track of radius 10 m with a constant speed of 20 m/s.

What force is required to keep the motorcycle moving in a circular path at this speed ?

200 N
400 N
2000 N
4000 N

2. A car going around a curve is acted upon by a centripetal force, F. If the speed of the car were twice as great,

the centripetal force necessary to keep it moving in the same path would be

F
2F
F/2
4F

3. A motorcycle travels around a flat circular track. If the speed of the motorcycle is increased, the force required

to keep it in the same circular path

decreases
increases
remains the same

4. As the distance between two masses increases, the gravitational
force of attraction between them

decreases
increases
remains the same

5. If the distance between two masses is tripled, the gravitational
force between them becomes

1/9 as great
1/3 as great
3 times as great
9 times as great

6. A rocket weighs 10,000 N at the earth's surface. If the rocket
rises to a height equal to the earth's radius above the

earth's surface, its weight will be

2500 N
5000 N
10,000 N
40,000 N

7. If the distance between two objects of constant mass is doubled,
the gravitational force of attraction between them is

halved
doubled
quartered
quadrupled

8. An object weighing 20.0 N at the earth's surface is moved to an
altitude where its weight is 10.0 N. The acceleration

due to gravity at this altitude is

2.45 m/s^{2}
4.90 m/s^{2}
9.80 m/s^{2}
19.6 m/s^{2}

9. An object weighing 16 N at the earth's surface is moved above the
earth a distance equal to the earth's radius. The

gravitational field strength at this new
position is

2.5 N/kg
4.9 N/kg
9.8 N/kg
4.0 N/kg

10. As the mass of a body increases, its gravitational force of
attraction on the Earth

decreases
increases
remains the same

11. The magnitude of the gravitational force between two objects is
20. N. If the mass of each object were doubled, the

magnitude of the gravitational force between
the objects would be

5.0 N
10. N
20.N
80. N

12. The gravitational force of attraction between two objects is 9.0
N. If the mass of one of the objects is tripled, the new

gravitational force of attraction will be

1.0 N
3.0 N
27 N
81 N

13. The gravitational force of attraction between two objects is F.
If the mass of each object is doubled, and the distance

between them is doubled, what is the new
gravitational force of attraction ?

1/4 F
1/2 F
F
4 F