BMST - Basic Math and Science Newton's Laws of Motion Questions and Answers 4 — Questions and Answers
Question 1: A hockey puck slides on a frictionless ice surface with constant velocity. What is the net force on the puck?
- Equal to its weight
- Greater than zero
- Zero (Correct answer)
- Equal to its momentum
Correct answer: Zero
Constant velocity means no acceleration, so by Newton's Second Law, the net force must be zero.
Question 2: When you jump off a boat onto a dock, the boat moves backward. This demonstrates:
- Newton's First Law
- Newton's Second Law
- Newton's Third Law (Correct answer)
- The principle of momentum loss
Correct answer: Newton's Third Law
Your push on the dock (action) results in an equal and opposite reaction that pushes the boat backward.
Question 3: If a net force of 60 N acts on a 12 kg object, what is the object's acceleration?
- 720 m/s²
- 0.2 m/s²
- 72 m/s²
- 5 m/s² (Correct answer)
Correct answer: 5 m/s²
Using a = F/m = 60/12 = 5 m/s².
Question 4: A ball is thrown upward and reaches its highest point. At that instant, ignoring air resistance, the net force on the ball is:
- Zero, because the ball momentarily stops
- Directed upward
- Directed downward due to gravity (Correct answer)
- Equal to the throwing force
Correct answer: Directed downward due to gravity
Gravity continuously acts downward regardless of the ball's momentary velocity.
Question 5: Which scenario best illustrates Newton's First Law?
- A car accelerating when the engine applies force
- A satellite orbiting Earth in a curved path
- Dishes sliding off a tablecloth pulled quickly (Correct answer)
- A swimmer pushing off a pool wall
Correct answer: Dishes sliding off a tablecloth pulled quickly
The dishes tend to remain in place (inertia) while the tablecloth is pulled away beneath them.
Question 6: According to Newton's Third Law, when a horse pulls a cart forward, the cart pulls the horse:
- Forward with a smaller force
- Backward with an equal force (Correct answer)
- Backward with a greater force
- Not at all
Correct answer: Backward with an equal force
The cart exerts an equal and opposite (backward) reaction force on the horse.
Question 7: An astronaut in deep space (no gravity, no air) throws a wrench. The wrench will:
- Slow down and stop
- Speed up over time
- Move at constant velocity indefinitely (Correct answer)
- Move in a curved path
Correct answer: Move at constant velocity indefinitely
With no external forces, Newton's First Law predicts the wrench continues at constant velocity forever.
BMST - Basic Math and Science Newton's Laws of Motion Questions and Answers 4
A hockey puck slides on a frictionless ice surface with constant velocity.
What is the net force on the puck?