Chapter 8 PHYSICAL SCIENCE : Force and Laws of Motion — Online MCQ Test
SCIENCE · CLASS 9th · Andhra State Board
Practice Chapter 8 PHYSICAL SCIENCE : Force and Laws of Motion with a free chapter-wise online MCQ test.
This chapter covers: This chapter details balanced unbalanced forces Newton three laws of motion inertia mass momentum and conservation of momentum principles..
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Chapter 8 PHYSICAL SCIENCE : Force and Laws of Motion — Important Questions & Answers
What is the SI unit of force?
- A. Newton
- B. Joule
- C. Pascal
- D. Watt
Answer: A. Newton
The SI unit of force is Newton (N), named after Isaac Newton.
The SI unit of force is Newton (N), named after Isaac Newton.
Which law of motion is also known as the Law of Inertia?
- A. Newton's First Law
- B. Newton's Second Law
- C. Newton's Third Law
- D. Law of Gravitation
Answer: A. Newton's First Law
Newton's first law defines inertia, stating an object remains in its state of rest or motion unless acted upon by an external force.
Newton's first law defines inertia, stating an object remains in its state of rest or motion unless acted upon by an external force.
When a force of 5N acts on a mass of 10kg, the acceleration produced is:
- A. 0.5 m/s²
- B. 2 m/s²
- C. 50 m/s²
- D. 5 m/s²
Answer: A. 0.5 m/s²
Using F=ma, acceleration a = F/m = 5/10 = 0.5 m/s².
Using F=ma, acceleration a = F/m = 5/10 = 0.5 m/s².
Action and reaction forces:
- A. Act on the same body
- B. Act on different bodies in opposite directions
- C. Always have different magnitudes
- D. Have a net force of non-zero value
Answer: B. Act on different bodies in opposite directions
Newton's third law states action and reaction are equal, opposite, and act on different bodies.
Newton's third law states action and reaction are equal, opposite, and act on different bodies.
Two objects of masses 100g and 200g are moving along the same line and direction with velocities 2 m/s and 1 m/s respectively. They collide and stick together. What is the velocity of the combined mass?
- A. 1.33 m/s
- B. 1.5 m/s
- C. 1.0 m/s
- D. 0.66 m/s
Answer: A. 1.33 m/s
Total initial momentum = (0.1 * 2) + (0.2 * 1) = 0.4. Total mass = 0.3kg. Final velocity = 0.4 / 0.3 = 1.33 m/s.
Total initial momentum = (0.1 * 2) + (0.2 * 1) = 0.4. Total mass = 0.3kg. Final velocity = 0.4 / 0.3 = 1.33 m/s.