NCERT Class-9 Science Solutions: Chapter 9-Force And Laws Of Motion Part 4

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Question 19:

Derive the unit of force using the second law of motion. A force of produces an acceleration of on a mass and an acceleration of on a mass . What acceleration would the same force provide if both the masses are tied together?

Answer:

This unit is also called newton. Its symbol is N.

Acceleration produced in M,

Question 20:

What is momentum? Write its SI unit. Interpret force in terms of momentum. Represent the following graphically

Answer:

SI unit of momentum is

Force = Rate of change in momentum

Momentum versus velocity when mass is fixed

Momentum versus mass when velocity is constant

Image Momentum - velocity graph

Image Momentum - Velocity Graph

Image Momentum - velocity graph