BMST - Basic Math and Science Newton's Laws of Motion Questions and Answers 5 ā Questions and Answers
Question 1: A 3 kg object and a 9 kg object are dropped from the same height in a vacuum. Which hits the ground first?
- The 9 kg object
- The 3 kg object
- They hit at the same time (Correct answer)
- Depends on their shape
Correct answer: They hit at the same time
In a vacuum, all objects fall with the same gravitational acceleration regardless of mass.
Question 2: A 4 kg object requires a net force of 16 N to accelerate. If the mass is doubled to 8 kg with the same force, the new acceleration is:
- 8 m/sĀ²
- 4 m/sĀ²
- 2 m/sĀ² (Correct answer)
- 1 m/sĀ²
Correct answer: 2 m/sĀ²
Original acceleration = 16/4 = 4 m/sĀ²; doubling mass halves acceleration to 2 m/sĀ².
Question 3: A skateboarder stands still on a skateboard and throws a ball forward. The skateboarder moves:
- Forward
- Backward (Correct answer)
- Upward
- Does not move
Correct answer: Backward
By Newton's Third Law, the reaction to throwing the ball forward pushes the skateboarder backward.
Question 4: What is the SI unit of force?
- Kilogram (kg)
- Joule (J)
- Newton (N) (Correct answer)
- Pascal (Pa)
Correct answer: Newton (N)
The Newton (N) is the SI unit of force, equivalent to kgĀ·m/sĀ².
Question 5: A net force causes a 6 kg object to accelerate at 2 m/sĀ². If the same force is applied to a 3 kg object, its acceleration would be:
- 1 m/sĀ²
- 2 m/sĀ²
- 4 m/sĀ² (Correct answer)
- 6 m/sĀ²
Correct answer: 4 m/sĀ²
Force = 6Ć2 = 12 N; applied to 3 kg: a = 12/3 = 4 m/sĀ².
Question 6: Which of the following is an example of Newton's First Law in everyday life?
- A ball accelerating when kicked
- Legs pushing off the ground when walking
- A passenger lurching forward when a bus brakes suddenly (Correct answer)
- A swimmer moving faster with stronger strokes
Correct answer: A passenger lurching forward when a bus brakes suddenly
The passenger's body resists the change in motion (inertia) and continues forward when the bus stops.
Question 7: Two ice skaters push off each other. Skater A has mass 50 kg and Skater B has mass 100 kg. If Skater A moves at 4 m/s, how fast does Skater B move (ignoring friction)?
- 4 m/s
- 8 m/s
- 2 m/s (Correct answer)
- 1 m/s
Correct answer: 2 m/s
Conservation of momentum: 50Ć4 = 100Ćv, so v = 2 m/s for Skater B.
BMST - Basic Math and Science Newton's Laws of Motion Questions and Answers 5
A 3 kg object and a 9 kg object are dropped from the same height in a vacuum.
Which hits the ground first?