Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 8

MEDIUM

9th CBSE

IMPORTANT

Earn 100

Explain friction, limiting friction and static friction with suitable examples.

Important Questions on Force and Laws of Motion

MEDIUM

9th CBSE

IMPORTANT

Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 9

A force of

50 N

acts on a body initially at rest. Find the momentum of the body at

3

second and

6

seconds after the force starts acting.

HARD

9th CBSE

IMPORTANT

Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 10

A bullet of mass $5 g$ travelling with a velocity of $18 km / h$ penetrates a wooden block and comes to rest in $0.01 s$ . Find

$(i)$ the distance through which it penetrates in the wooden block;

$(i i)$ the value of retarding force of the block.

MEDIUM

9th CBSE

IMPORTANT

Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 11

A wooden trolley of mass

3 kg

is mounted on wheels on horizontal rails. Neglecting friction and air resistance, what will be the final velocity of the trolley if a bullet of mass

2 g

is fired into it with a horizontal velocity of

800 m / s

along the direction of the rails.

MEDIUM

9th CBSE

IMPORTANT

Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 12

A rubber ball of mass

0.25 kg

is thrown against a wall. It strikes the wall normally with a velocity of

50 m / s

and rebounds with the same speed in the opposite direction. Calculate the impulse of the force exerted by the wall on the ball.

MEDIUM

9th CBSE

IMPORTANT

Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 13

Two blocks of mass $m_{1} = 1 kg$ and $m_{2} = 2 kg$ are placed in contact on a frictionless horizontal surface. A force of $10 N$ is acting on $m_{1}$ . What is the acceleration of $m_{1}$ and $m_{2}$ . What is the value of action and reaction between the blocks?

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MEDIUM

9th CBSE

IMPORTANT

Secondary Physics>Chapter 2 - Force and Laws of Motion>EXERCISES>Q 14

A constant retarding force of $100 N$ is applied to a body of mass $60 kg$ moving initially with a speed of $18 km / h$ . How long does the body take to come to halt?