Physics 12 - Unit 2 Quiz

Name:

True/False

Indicate whether the sentence or statement is true or false.

One joule is one newton metre squared per second squared.

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

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.

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

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

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

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.

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.

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.

Figure 1

16.

The magnitude of the normal force of the hillside acting on the toboggan is

a.	mg cos b
b.	F_A sin f
c.	mg cos b F_A sin f
d.	mg cos b + F_A sin f
e.	(mg cos b + F_A sin f)

17.

The magnitude of the applied force _A is

a.
b.
c.
d.	F_K + F_N
e.	F_K + F_N mg

18.

The work done by the applied force in moving the toboggan the length of the hill, L, is

a.	F_AL
b.	F_KL
c.	(F_A F_K)L
d.
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.	2F	d.	F
b.		e.	zero
c.	Fr

20.

A motorcycle of mass of m, with a driver of mass

, is travelling at speed v. Later, it is travelling with the same driver, as well as a passenger of mass

, 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

Figure 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.
b.	0
c.	v
d.	2v
e.

Questions 24 to 26 relate to Figure 3.

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 v_F, v_G, and v_H, then

a.	v_F = v_G = v_H
b.	v_F > v_G > v_H
c.	v_F < v_G < v_H
d.	v_F = v_G, but v_H 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 2r_E 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 E_F, E_G, and E_H, then

a.	E_F = E_G = E_H
b.	E_F > E_G > E_H
c.	E_F < E_G < E_H
d.	E_F = E_G, but E_H has no defined escape energy
e.	the energies cannot be compared with the information given

27.

If the distance between a spacecraft and Jupiter increases by a factor of 4, the magnitude of Jupiter’s gravitational field at the position of the spacecraft

a.	increases by a factor of 4
b.	decreases by a factor of 4
c.	increases by a factor of 16
d.	decreases by a factor of 16
e.	decreases by a factor of 2

28.

If the Sun’s mass were 8 times its current value, and Earth’s period of revolution around the Sun retained its current value, then the average distance from Earth to the Sun, in terms of its current value, r, would be

a.	8r
b.
c.
d.	2r
e.	none of these

Completion

Complete each sentence or statement.

29.

______ first used a telescope to observe the moons of a distant planet.

30.

______ first proposed that the orbits of planets are ellipses.

31.

The SI unit of energy is named after ______ .

32.

______ provided the data used to derive the laws of planetary motion.

33.

______ first analyzed the relationship between the force applied to a spring and the spring’s stretch or compression.

34.

The radius of a black hole is named after ______ .

35.

The area under a force-displacement graph represents ______ .

36.

The slope of a line on a force-stretch graph represents ______ .

37.

The area under the line on a force-time graph represents ______ .

38.

The slope of a line on a momentum-time graph represents ______ .

39.

The area under the line on a kinetic friction-displacement graph represents ______ .

40.

The slope of the line on a graph of r³ versus T², for a satellite in orbit around Earth, represents ______ .

41.

A collision in which the two objects stick together is called a(n) ______ collision.

42.

In an elastic collision, the total kinetic energy after the collision ______ the total kinetic energy before the collision.

43.

A collision in which the decrease in kinetic energy is the maximum possible is called a(n) _______ .

44.

The eccentricity of a circle is ______ .

45.

At the centre of a black hole is a region called ______ .

46.

The distance from the centre of this region to the event horizon is called the ______ .

Figure 4(a) represents the motion of a truck with positions separated by equal time intervals of 5.0 s.

Figure 4

Choose the graph in Figure 4(b) that best represents:

47.

the truck’s momentum

48.

the truck’s kinetic energy

Matching

Match the letter of the following mathematical relationships with the quantity that it best defines.

a.		h.
b.		i.	(F cos )d
c.		j.	F_Kd
d.		k.	kx²
e.		l.	±kx
f.		m.
g.	=

49.

impulse

50.

law of conservation of momentum

51.

kinetic energy

52.

thermal energy

53.

elastic potential energy

54.

escape speed

55.

gravitational potential energy

56.

Kepler’s third-law constant

57.

frequency of a mass-spring system in SHM