Question

Question 11


If a motorcyclist has a mass of 120 kg and is biking down a road at a rate of 30 m/s, what is the kinetic energy?

a
54,000 J
b
108,000 J
c
216,000 J
d
1,800 J
Question 12
Which one of the following objects will have the highest kinetic energy?

Object

Mass (kg)

Velocity (m/s)

Object 1

2

5

Object 2

4

15

Object 3

6

3

Object 4

8

2

a
Object 1
b
Object 2
c
Object 3
d
Object 4
Question 13


Using the provided formula, solve for velocity.

An object has a kinetic energy of 48 J and a mass of 6 kg, how fast is the object moving?

a
4 m/s^2
b
8 m/s^2
c
16 m/s^2
d
3 m/s^2
Question 14
The potential energy of a system can be changed by varying the position of objects in the system.

At which point do the coaster cars have the most potential energy?



a
A
b
B
c
C
d
D
Question 15
The potential energy of a system can be changed by varying the position of objects in the system.

At which point do the coaster cars have the most kinetic energy?



a
A
b
B
c
C
d
D
Question 16
Calculate the potential energy of a 20 kg cart rolling through the track at point A.

PE = m x g x h KE = 0.5 x m x v2



a
80 J
b
981 J
c
40 J
d
1,962 J
Question 17
Calculate the kinetic energy of a 20 kg cart rolling through the track at point A.

PE = m x g x h KE = 0.5 x m x v2



a
40 J
b
1,962 J
c
80 J
d
981 J
Question 18


At which point on the slide would an object sliding down the slide have the most amount of potential energy?

a
C
b
A
c
B
Question 19
Match the definition to the correct term.

Column A
1.
energy transfer:
energy transfer
2.
mechanical energy:
mechanical energy
3.
conservative force:
conservative force
4.
non-conservative force:
non-conservative force
Column B
a.a combination of kinetic energy and potential energy
b.the movement of kinetic energy from one object to another
c.any force for which the final displacement of an object is the only factor that determines the work done by the force.
d.force that dissipates energy

Answer 1

Question 11: a (54,000 J)
- KE = 1/2 m v^2 = 0.5·120·30^2 = 54,000 J

Question 12: b (Object 2)
- KE1 = 0.5·2·5^2 = 25 J
- KE2 = 0.5·4·15^2 = 450 J (largest)
- KE3 = 0.5·6·3^2 = 27 J
- KE4 = 0.5·8·2^2 = 16 J

Question 13: a (4 m/s)
- v = sqrt(2KE/m) = sqrt(2·48/6) = sqrt(16) = 4 m/s

Question 14: a (A)
- Most potential energy at the highest point (A)

Question 15: c (C)
- Most kinetic energy at the lowest point (C)

Question 16: b (981 J)
- PE = mgh = 20·9.81·5 ≈ 981 J (height at A = 5 m)

Question 17: d (981 J)
- If total initial PE = 1962 J (at 10 m) and A is at 5 m, KE_A = total − PE_A = 1962 − 981 = 981 J
(So KE at A ≈ 981 J)

Question 18: b (A)
- Most potential energy at the highest point (A)

Question 19: matchings
1 → b (energy transfer = the movement of kinetic energy from one object to another)
2 → a (mechanical energy = combination of kinetic and potential energy)
3 → c (conservative force = work depends only on initial and final positions)
4 → d (non-conservative force = force that dissipates energy)