EIAT Forces, Torque, and Motion 2 — Questions and Answers
Question 1: A sheave has a radius of 0.4 m and a rope tension of 500 N on one side. What torque does this tension apply to the sheave?
- 125 N·m
- 200 N·m (Correct answer)
- 250 N·m
- 400 N·m
Correct answer: 200 N·m
Torque = Force × radius = 500 N × 0.4 m = 200 N·m.
Question 2: An elevator car decelerates from 4 m/s to 0 m/s in 2 seconds. What is the magnitude of its deceleration?
- 0.5 m/s²
- 1 m/s²
- 2 m/s² (Correct answer)
- 8 m/s²
Correct answer: 2 m/s²
Deceleration = Δv / Δt = 4 / 2 = 2 m/s².
Question 3: Two ropes support a 1,200 N load equally. What is the tension in each rope?
- 300 N
- 600 N (Correct answer)
- 900 N
- 1,200 N
Correct answer: 600 N
Each rope carries half the load: 1,200 / 2 = 600 N.
Question 4: A counterweight reduces the net force a motor must lift. If the car weighs 8,000 N and the counterweight is 5,000 N, what net upward force is needed to raise the car?
- 1,500 N
- 3,000 N (Correct answer)
- 5,000 N
- 8,000 N
Correct answer: 3,000 N
Net force = Car weight − Counterweight = 8,000 − 5,000 = 3,000 N.
Question 5: Which law of motion explains why a passenger feels pushed backward when an elevator accelerates upward?
- Newton's First Law (Correct answer)
- Newton's Second Law
- Newton's Third Law
- Hooke's Law
Correct answer: Newton's First Law
Newton's First Law (inertia) explains that the passenger's body resists the change in motion and appears to be pushed in the opposite direction.
Question 6: A motor exerts 600 N·m of torque on a drum of radius 0.3 m. What rope tension does the drum produce?
- 180 N
- 600 N
- 1,200 N
- 2,000 N (Correct answer)
Correct answer: 2,000 N
Tension = Torque / radius = 600 / 0.3 = 2,000 N.
Question 7: An object moving in a circle experiences centripetal acceleration directed:
- Tangentially to the circle
- Away from the center
- Toward the center (Correct answer)
- Opposite to the velocity
Correct answer: Toward the center
Centripetal acceleration always points toward the center of the circular path.
EIAT Forces, Torque, and Motion 2
A sheave has a radius of 0.4 m and a rope tension of 500 N on one side.
What torque does this tension apply to the sheave?