Question

(a) State the law that provides the formula for measuring force, and the law that provides the definition of force.
(b)) Velocity-time graph of a 50 gm marble rolling on the floor is given below.
Find : (i) time in which it stops. (ii) negative acceleration produced on it. (iii)positive force acting on the marble.

CBSE Class IX Science LA (5 Marks)

Answer 1

(a) Measuring force is given by Newton’s 2nd law. Second law of motion gives us a method to measure the force acting on an object, as force is the product of its mass and acceleration. Definition of force is given by Newton’s 1st law.
(b)
From graph,
(i) t = 25 s
(ii) a = 300/25
= 1.2 m/s2
(iii) F = ma
= (50/1000)× 1.2
=
0.06 N

Answer 2

Answer:

Explanation:

(a) Measuring force is given by Newton’s 2nd law. Second law of motion gives us a method to measure the force acting on an object, as force is the product of its mass and acceleration. Definition of force is given by Newton’s 1st law.

(b)

From graph,

(i) t = 25 s

(ii) a = 300/25

= 1.2 m/s2

(iii) F = ma

= (50/1000)× 1.2

=

0.06 N