What is Force ? (āĻŦāϞ āĻāĻŋ ?)
- What is Momentum? (āĻā§°āĻŦā§āĻ āĻāĻŋ ?) : View Paper
- Momentum vs Force (āĻā§°āĻŦā§āĻ āĻŦāύāĻžāĻŽ āĻŦāϞ) : View Paper
- Difference between Momentum vs Force / āĻā§°āĻŦā§āĻ āĻā§°ā§ āĻŦāϞ⧰ āĻŽāĻžāĻā§° āĻĒāĻžā§°ā§āĻĨāĻā§āϝ : View Paper
Note:
- Force can start or stop motion. āĻŦāϞ⧠āĻāϤāĻŋ āĻā§°āĻŽā§āĻ āĻŦāĻž āĻŦāύā§āϧ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
- It can change the speed of an object. āĻ āĻŦāϏā§āϤā§ā§° āĻŦā§āĻ āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
- It can change the direction of motion. āĻ āĻŦāϏā§āϤā§ā§° āĻāϤāĻŋā§° āĻĻāĻŋāĻļ āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
- Formula / āϏā§āϤā§ā§°: F = m × a
- SI Unit / SI āĻāĻāĻ: Newton (N) / āύāĻŋāĻāĻāύ (N)
- Force is a vector quantity because it has both magnitude and direction. āĻŦāϞ āĻāĻāĻž āϏāĻĻāĻŋāĻļ (Vector) ā§°āĻžāĻļāĻŋ, āĻāĻžā§°āĻŖ āĻāϝāĻŧāĻžā§° āĻŽāĻžāύ āĻā§°ā§ āĻĻāĻŋāĻļ āĻĻā§āϝāĻŧā§āĻāĻž āĻĨāĻžāĻā§āĨ¤
Examples / āĻāĻĻāĻžāĻšā§°āĻŖPushing a box across the floor. āĻŽāĻāĻŋāϝāĻŧāĻžā§° āĻāĻĒā§°āϤ āĻāĻāĻž āĻŦāĻžāĻāĻ āĻ ā§āϞāĻžāĨ¤
- Kicking a football. āĻĢā§āĻāĻŦāϞāϤ āϞāĻžāĻĨāĻŋ āĻŽā§°āĻžāĨ¤
Tip:
- Force changes the motion of an object. āĻŦāϞ⧠āĻā§āύ⧠āĻŦāϏā§āϤā§ā§° āĻāϤāĻŋ āϏāϞāύāĻŋ āĻā§°ā§āĨ¤
- More force produces more acceleration (for the same mass).
āĻāĻā§ āĻā§°āϤ āĻ āϧāĻŋāĻ āĻŦāϞ āĻĒā§ā§°āϝāĻŧā§āĻ āĻā§°āĻŋāϞ⧠āĻ āϧāĻŋāĻ āϤā§āĻŦā§°āĻŖ āĻā§āĻĒāύā§āύ āĻšāϝāĻŧāĨ¤
Physics – Force (MCQs)
1. Force is defined as: āĻŦāϞāĻ āĻā§āύā§āĻā§ āϏāĻāĻā§āĻāĻžāϝāĻŧāĻŋāϤ āĻā§°āĻž āĻšāϝāĻŧ ?
A) Energy produced by an object B) A push or pull acting on an object C) Speed of an object D) Quantity of motion
Ans: B) A push or pull acting on an object
Explanation: Force is a push or pull that can change the state of motion of an object. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻŦāϞ āĻšā§āĻā§ āĻ ā§āϞāĻž āĻŦāĻž āĻāĻžāύ, āϝāĻŋāϝāĻŧā§ āĻŦāϏā§āϤā§ā§° āĻāϤāĻŋā§° āĻ ā§ąāϏā§āĻĨāĻž āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
2. The SI unit of force is: āĻŦāϞ⧰ SI āĻāĻāĻ āĻāĻŋ ?
A) Joule B) kg·m/s C) Newton (N) D) Watt
Ans: C) Newton (N)
Explanation: The SI unit of force is Newton (N). āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻŦāϞ⧰ SI āĻāĻāĻ āĻšā§āĻā§ āύāĻŋāĻāĻāύ (N)āĨ¤
3. Which formula is used to calculate force ? āĻŦāϞ āύāĻŋā§°ā§āĻŖāϝāĻŧ āĻā§°āĻŋāĻŦāϞ⧠āĻā§āύāĻā§ āϏā§āϤā§ā§° āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āĻā§°āĻž āĻšāϝāĻŧ ?
A) p = mv B) F = ma C) V = IR D) W = Fs
Ans: B) F = ma
Explanation: According to Newton's Second Law, Force = Mass × Acceleration. āĻŦā§āϝāĻžāĻā§āϝāĻž: āύāĻŋāĻāĻāύ⧰ āĻĻā§āĻŦāĻŋāϤā§āϝāĻŧ āĻāϤāĻŋ āύāĻŋāϝāĻŧāĻŽ āĻ āύā§āϏ⧰āĻŋ āĻŦāϞ = āĻā§° × āϤā§āĻŦā§°āĻŖāĨ¤
4. Force is a ______ quantity. āĻŦāϞ āĻāĻāĻž ______ ā§°āĻžāĻļāĻŋāĨ¤
A) Scalar B) Vector C) Dimensionless D) Fundamental
Ans: B) Vector
Explanation: Force has both magnitude and direction. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻŦāϞ⧰ āĻŽāĻžāύ āĻā§°ā§ āĻĻāĻŋāĻļ āĻĻā§āϝāĻŧā§āĻāĻž āĻĨāĻžāĻā§āĨ¤
5. Which of the following can a force do ? āϤāϞ⧰ āĻā§āύāĻā§ āĻāĻžāĻŽ āĻŦāϞ⧠āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§ ?
A) Change the speed of an object B) Change the direction of motion
C) Start or stop motion D) All of the above
Ans: D) All of the above
Explanation: Force can start, stop, speed up, slow down, or change the direction of an object. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻŦāϞ⧠āĻŦāϏā§āϤ⧠āĻāĻāĻžāĻ āĻāϞāĻžāĻŦ āĻĒāĻžā§°ā§, ā§°āĻāĻžāĻŦ āĻĒāĻžā§°ā§, āĻŦā§āĻ āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§ āĻā§°ā§ āĻāϤāĻŋā§° āĻĻāĻŋāĻļā§ āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
6. A force of 20 N acts on a body of mass 4 kg. The acceleration is: 20 N āĻŦāϞ 4 kg āĻā§°ā§° āĻāĻāĻž āĻŦāϏā§āϤā§ā§° āĻāĻĒā§°āϤ āĻĒā§ā§°āϝāĻŧā§āĻ āĻā§°āĻž āĻšā§āĻā§āĨ¤ āϤā§āĻŦā§°āĻŖ āĻāĻŋāĻŽāĻžāύ ?
A) 2 m/s² B) 5 m/s² C) 10 m/s² D) 80 m/s²
Ans: B) 5 m/s²
Explanation: a = F/m = 20/4 = 5 m/s2. āĻŦā§āϝāĻžāĻā§āϝāĻž: āϤā§āĻŦā§°āĻŖ = āĻŦāϞ ÷ āĻā§° = 20 ÷ 4 = 5 m/s²
7. Who gave the formula F= ma ? F = ma āϏā§āϤā§ā§°āĻā§ āĻā§āύ⧠āĻĻāĻŋāĻāĻŋāϞ ?
A) Galileo B) Sir Isaac Newton C) Einstein D) Archimedes
Ans: B) Sir Isaac Newton
Explanation: This is Newton's Second Law of Motion. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻāĻāĻā§ āύāĻŋāĻāĻāύ⧰ āĻĻā§āĻŦāĻŋāϤā§āϝāĻŧ āĻāϤāĻŋ āύāĻŋāϝāĻŧāĻŽāĨ¤
8. If the mass remains constant, increasing the force will: āĻā§° āĻāĻā§ āĻĨāĻžāĻāĻŋāϞ⧠āĻŦāϞ āĻŦā§āĻĻā§āϧāĻŋ āĻā§°āĻŋāϞ⧠āĻāĻŋ āĻš'āĻŦ ?
A) Decrease acceleration B) Increase acceleration C) No change D) Decrease momentum
Ans: B) Increase acceleration
Explanation: According to F = ma, for the same mass, greater force produces greater acceleration. āĻŦā§āϝāĻžāĻā§āϝāĻž: F = ma āĻ āύā§āϏ⧰āĻŋ, āĻāĻā§ āĻā§°āϤ āĻ āϧāĻŋāĻ āĻŦāϞ āĻĒā§ā§°āϝāĻŧā§āĻ āĻā§°āĻŋāϞ⧠āĻ āϧāĻŋāĻ āϤā§āĻŦā§°āĻŖ āĻā§āĻĒāύā§āύ āĻšāϝāĻŧāĨ¤
2 Marks PYQ
1. What is Force ? Write its formula. āĻŦāϞ (Force) āĻāĻŋ ? āĻāϝāĻŧāĻžā§° āϏā§āϤā§ā§° āϞāĻŋāĻāĻžāĨ¤
Ans / āĻāϤā§āϤ⧰: Force is a push or pull acting on an object. It can change the state of rest or motion of an object. āĻŦāϞ āĻšā§āĻā§ āĻā§āύ⧠āĻŦāϏā§āϤā§ā§° āĻāĻĒā§°āϤ āĻĒā§ā§°āϝāĻŧā§āĻ āĻā§°āĻž āĻ ā§āϞāĻž āĻŦāĻž āĻāĻžāύāĨ¤ āĻ āĻā§āύ⧠āĻŦāϏā§āϤā§ā§° āϏā§āĻĨāĻŋā§° āĻ ā§ąāϏā§āĻĨāĻž āĻŦāĻž āĻāϤāĻŋā§° āĻ ā§ąāϏā§āĻĨāĻž āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
Formula / āϏā§āϤā§ā§°: F = m × a
2. Write any two effects of Force. āĻŦāϞ⧰ āϝāĻŋāĻā§āύ⧠āĻĻā§āĻāĻž āĻĒā§ā§°āĻāĻžā§ą āϞāĻŋāĻāĻžāĨ¤
Ans / āĻāϤā§āϤ⧰: i. Force can start or stop the motion of an object. āĻŦāϞ⧠āĻā§āύ⧠āĻŦāϏā§āϤā§ā§° āĻāϤāĻŋ āĻā§°āĻŽā§āĻ āĻŦāĻž āĻŦāύā§āϧ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§āĨ¤
ii. Force can change the speed or direction of an object. āĻŦāϞ⧠āĻā§āύ⧠āĻŦāϏā§āϤā§ā§° āĻŦā§āĻ āĻŦāĻž āĻāϤāĻŋā§° āĻĻāĻŋāĻļ āϏāϞāύāĻŋ āĻā§°āĻŋāĻŦ āĻĒāĻžā§°ā§
3. Write the SI unit of Force.āĻŦāϞ⧰ SI āĻāĻāĻ āϞāĻŋāĻāĻžāĨ¤
Ans / āĻāϤā§āϤ⧰: The SI unit of force is Newton (N). āĻŦāϞ⧰ SI āĻāĻāĻ āĻšā§āĻā§ āύāĻŋāĻāĻāύ (N)āĨ¤
4. Why is Force called a vector quantity ? āĻŦāϞāĻ āϏāĻĻāĻŋāĻļ (Vector) ā§°āĻžāĻļāĻŋ āĻāĻŋāϝāĻŧ āĻā§ā§ąāĻž āĻšāϝāĻŧ ?
Ans / āĻāϤā§āϤ⧰: Force is a vector quantity because it has both magnitude and direction. āĻŦāϞāĻ āϏāĻĻāĻŋāĻļ ā§°āĻžāĻļāĻŋ āĻā§ā§ąāĻž āĻšāϝāĻŧ, āĻāĻžā§°āĻŖ āĻāϝāĻŧāĻžā§° āĻŽāĻžāύ āĻā§°ā§ āĻĻāĻŋāĻļ āĻĻā§āϝāĻŧā§āĻāĻž āĻĨāĻžāĻā§āĨ¤
5. State Newton's Second Law of Motion. āύāĻŋāĻāĻāύ⧰ āĻĻā§āĻŦāĻŋāϤā§āϝāĻŧ āĻāϤāĻŋ āύāĻŋāϝāĻŧāĻŽ āϞāĻŋāĻāĻžāĨ¤
Ans / āĻāϤā§āϤ⧰: Newton's Second Law states that the force acting on an object is equal to the product of its mass and acceleration. āύāĻŋāĻāĻāύ⧰ āĻĻā§āĻŦāĻŋāϤā§āϝāĻŧ āĻāϤāĻŋ āύāĻŋāϝāĻŧāĻŽ āĻ āύā§āϏ⧰āĻŋ, āĻā§āύ⧠āĻŦāϏā§āϤā§ā§° āĻāĻĒā§°āϤ āĻĒā§ā§°āϝāĻŧā§āĻ āĻšā§ā§ąāĻž āĻŦāϞ āĻŦāϏā§āϤā§āĻā§ā§° āĻā§° āĻā§°ā§ āϤā§āĻŦā§°āĻŖā§° āĻā§āĻŖāĻĢāϞ⧰ āϏāĻŽāĻžāύāĨ¤
Formula / āϏā§āϤā§ā§°: F = m × a
6. A 3 kg box is accelerated at 2 m/s². Find the force. (āĻāĻāĻž 3 kg āĻā§°ā§° āĻŦāĻžāĻāĻ 2 m/s² āϤā§āĻŦā§°āĻŖ āϞāĻžāĻ āĻā§°āĻŋāĻā§āĨ¤ āĻĒā§ā§°āϝāĻŧā§āĻ āĻšā§ā§ąāĻž āĻŦāϞ (Force) āύāĻŋā§°ā§āĻŖāϝāĻŧ āĻā§°āĻžāĨ¤)
Solution | āϏāĻŽāĻžāϧāĻžāύ
Fnet = ma
1st: Formula | āϏā§āϤā§ā§° : F = ma
Where / āϝ'āϤ, F = Force (āĻŦāϞ), m = Mass (āĻā§°), a = Acceleration (āϤā§āĻŦā§°āĻŖ)
F = ma = 3×2 = 6N
Ans | āĻāϤā§āϤ⧰: Force(āĻŦāϞ) = 6 N
Note: More force causes a greater change in motion.(āĻ āϧāĻŋāĻ āĻŦāϞ āĻĒā§ā§°āϝāĻŧā§āĻ āĻā§°āĻŋāϞ⧠āĻŦāϏā§āϤā§ā§° āĻāϤāĻŋāϤ āĻ āϧāĻŋāĻ āĻĒā§°āĻŋā§ąā§°ā§āϤāύ āĻšāϝāĻŧāĨ¤)
Tip | āĻāĻŋāĻĒāĻ : More Force = More Acceleration (for the same mass). (āĻāĻā§ āĻā§°ā§° āĻā§āώā§āϤā§ā§°āϤ āĻ āϧāĻŋāĻ āĻŦāϞ = āĻ āϧāĻŋāĻ āϤā§āĻŦā§°āĻŖāĨ¤)
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