Puzzles on Force
1. A force of 20 N is applied to a box, causing it to move 5 meters. What is the work done?
Hint: Work done = Force × Distance
Answer: 100 Joules
2. A ball is thrown upwards. Which force acts against its motion?
Hint: Consider the force pulling objects towards the Earth.
Answer: Gravitational force
3. A spring stretches by 2 cm when a force of 5 N is applied. What is the spring constant?
Hint: Spring constant (k) = Force / Extension
Answer: 250 N/m
4. What is the net force acting on an object at rest?
Hint: An object at rest has no acceleration.
Answer: 0 N
5. A car moves with constant velocity. What can be said about the net force acting on it?
Hint: Constant velocity implies no acceleration.
Answer: The net force is 0 N.
6. What happens to the acceleration of an object if the force acting on it is doubled?
Hint: Acceleration is directly proportional to force.
Answer: Acceleration doubles.
7. If the mass of an object is 10 kg and it accelerates at 3 m/s², what is the force acting on it?
Hint: Force = Mass × Acceleration
Answer: 30 N
8. Which force opposes the motion of an object sliding on a rough surface?
Hint: It starts with 'F'.
Answer: Friction
9. What is the unit of force in the SI system?
Hint: It is named after a famous scientist.
Answer: Newton (N)
10. A 50 N force is applied to push a box. If the box does not move, which force balances the applied force?
Hint: The force opposes motion initiation.
Answer: Static friction