Name: 
 

Physics 12 - Unit 2 Quiz


True/False
Indicate whether the sentence or statement is true or false.
 

1. 
One joule is one newton metre squared per second squared.
 

2. 
The force constant of a spring can be said to measure the “stiffness” of the spring.
 

3. 
Two boxes are being moved on level terrain, one on Earth, the other on the Moon. If the displacement and coefficient of kinetic friction are the same, then the thermal energy produced by the kinetic friction would also be the same.
 

4. 
Impulse and momentum are the same quantity because their base SI units are equivalent.
 

5. 
Two figure skaters, initially stationary, push away from each other. Just after this interaction, the total momentum of this system is zero.
 

6. 
The only type of collision in which momentum is not conserved is a completely inelastic collision.
 

7. 
The gravitational field strength at a location in the Sun’s gravitational field is inversely proportional to the distance between that location and the Sun’s centre.
 

8. 
The work done by the force of Earth’s gravity acting on a satellite in circular motion around Earth is positive because the satellite is always accelerating toward Earth.
 

9. 
In the heliocentric model, Earth is at the centre of the universe and all other celestial bodies revolve around it.
 

10. 
The Sun is located at the centre of a planet’s orbit.
 

11. 
The speed of a satellite in elliptical orbit around Earth is independent of the satellite’s position in its orbit.
 

12. 
A black hole has an extremely strong magnetic field.
 

13. 
A black hole is a celestial body with an escape speed equal to or greater than the speed of light.
 

14. 
X rays and gamma rays can escape from a black hole, even though visible light cannot.
 

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

15. 
If you were to climb a ladder that was your height, the work you would do against the force of gravity is approximately
a.
101 J
b.
102 J
c.
103 J
d.
104 J
e.
105 J
 
 
For questions 16 to 18, refer to Figure 1, in which a toboggan is pulled up a hill of length L at a constant velocity.
p12u2_files/i0180000.jpg

Figure 1
 

16. 
The magnitude of the normal force of the hillside acting on the toboggan is
a.
mg cos b
b.
FA sin f
c.
mg cos b p12u2_files/i0190000.jpg FA sin f
d.
mg cos b + FA sin f
e.
p12u2_files/i0190001.jpg(mg cos b + FA sin f)
 

17. 
The magnitude of the applied force p12u2_files/i0200000.jpgA is
a.
p12u2_files/i0200001.jpg
b.
p12u2_files/i0200002.jpg
c.
p12u2_files/i0200003.jpg
d.
FK + FN
e.
FK + FN p12u2_files/i0200004.jpg mg
 

18. 
The work done by the applied force in moving the toboggan the length of the hill, L, is
a.
FAL
b.
FKL
c.
(FA p12u2_files/i0210000.jpg FK)L
d.
p12u2_files/i0210001.jpg
e.
none of these
 

19. 
A satellite in a circular orbit of radius r around Mars experiences a force of gravity of magnitude F exerted by Mars. The work done by this force on the satelliete as it travels halfway around its orbit is
a.
2Fp12u2_files/i0220000.jpg
d.
Fp12u2_files/i0220001.jpg
b.
p12u2_files/i0220002.jpg
e.
zero
c.
Fr
 

20. 
A motorcycle of mass of m, with a driver of mass p12u2_files/i0230000.jpg, is travelling at speed v. Later, it is travelling with the same driver, as well as a passenger of mass p12u2_files/i0230001.jpg, at a speed 0.80v. The motorcycle’s new kinetic energy is
a.
equal to the initial kinetic energy
b.
greater than the initial kinetic energy by a factor of 0.75
c.
less than the initial kinetic energy by a factor of 0.75
d.
greater than the initial kinetic energy by a factor of 1.3
e.
less than the initial kinetic energy by a factor of 1.3
 

21. 
Three stones are thrown with identical initial speeds from the top of a cliff into the water below (Figure 2). Air resistance is negligible. The speeds with which stones 1, 2, and 3 strike the water are
p12u2_files/i0240000.jpgFigure 2
a.
v1 = v3 > v2
b.
v2 > v1 = v3
c.
v1 > v2 > v3
d.
v3 > v2 > v1
e.
v1 = v2 = v3
 

22. 
The contact times in collisions between a baseball and a baseball bat are typically a few
a.
seconds
b.
nanoseconds
c.
microseconds
d.
milliseconds
e.
kiloseconds
 

23. 
A billiard ball, moving with speed v, collides head-on with a stationary ball of the same mass. After the collision, the billiard ball that was initially moving is at rest. The speed of the other ball in terms of v is
a.
p12u2_files/i0260000.jpg
b.
0
c.
v
d.
2v
e.
p12u2_files/i0260001.jpg
 
 
Questions 24 to 26 relate to Figure 3.

p12u2_files/i0270000.jpg

Figure 3
This graph shows the kinetic energy given to three rockets (F, G, and H) of equal mass as they are launched from Earth's surface.
 

24. 
If the escape speeds of the rockets are vF, vG, and vH, then
a.
vF = vG = vH
b.
vF > vG > vH
c.
vF < vG < vH
d.
vF = vG, but vH has no defined escape speed
e.
the speeds cannot be compared with the information given
 

25. 
In the situation of Figure 3, which of the following statements is true?
a.
H will rise to an altitude of 2rE above Earth’s surface and remain there.
b.
F and G will escape and have zero speed after escaping.
c.
Only F will escape, but it will have zero speed after escaping.
d.
Only F will escape and it will have a nonzero speed after escaping.
e.
none of these
 

26. 
If the escape energies of the rockets are EF, EG, and EH, then
a.