Laws of Motion Exe-3A Very Short Answer Physics Class-9 ICSE Selina Publishers

Laws of Motion Exe-3A Contact and Non-contact Forces Very Short Answer Type for Class-9 ICSE Concise Physics. There is the solutions of Very short Answer type Questions of your latest textbook which is applicable in 2023-24 academic sessionVisit official Website CISCE for detail information about ICSE Board Class-9.

Laws of Motion Exe-3A Contact and Non-contact Forces Very Short Answer 

(ICSE Class – 9 Physics Concise Selina Publishers)

Board ICSE
Class 9
Subject Physics
Writer / Publication Concise selina Publishers
Chapter-3 Laws of Motion
Exe – 3A Contact and Non-contact Forces
Topics Solution of Exe-3(A) Very Short Answer Type
Academic Session 2023-2024

Exe-3A Contact and Non-contact Forces Very Short Answer Type

Ch-3 Laws of Motion Physics Class-9 ICSE Concise

Page 65

Question 1. Define a contact Force.

Answer:  contact force is any force that occurs as a result of two objects making contact with each other.

Question 2. Define a non-contact Force.

Answer: A non-contact force is a force applied to an object by another body that is not in direct contact with it. Non-contact forces come into play when objects do not have physical contact between them or when a force is applied without any interaction.

Question 3. Classify the following amongst contact and non – contact forces:

(a) Frictional force

(b) Normal reaction force

(c) Force of tension in a string

(d) Gravitational force

(e) Electrostatic force

(f) Magnetic force

Answer:

Contact force: (a) frictional force (b) normal reaction force (c) force of tension in a string

Non-contact force: (d) gravitational force (e) electric force (f) magnetic force

(Laws of Motion Exe-3A Very Short Class-9 ICSE)

Question 4. Give one example in each case where :

(a) The force is of contact, and

(b) Force is at a distance

Answer:

(a) Force exerted on two bodies during collision.

(b) Magnetic force between magnetic poles.

Question 5. State one factor on which the magnitude of a non-contact force depends. How does it depend on the factor stated by you?

Answer :

The magnitude of non-contact force on two bodies depends on the distance of separation between them.

The force decreases as the distance of separation increases.

The force is inversely proportional to the square of the distance of separation.

Question 6. The separation between two masses is reduced to half. How is the magnitude of gravitational force between them affected?

Answer :

The magnitude of gravitational force between two masses will become four times as gravitational force varies inversely as the square of distance of separation.

Question 7. Give one example in each of the following cases where a force:

(a)Stops a moving body.

(b)Moves a stationary body.

(c) Changes the size of a body.

(d) Changes the shape of a body.

Answer :

(a)A fielder on the ground stops a moving ball by applying a force with his hands.

(b) The pull exerted by horse makes a cart moves.

(c) In a cycle pump, when the piston is lowered, the air is compressed to occupy a less volume.

(d) On pressing a piece of rubber, its shape changes.

—  : End of Laws of Motion Exe-3A Contact and Non-contact Forces Very Short Answer Type  Solutions :–

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