Instantaneous Force and Impulse

Q.

A force of 50 dynes is acted on a body of mass 5 g which is at rest for an interval of 3 seconds, then impulse is

1. 

2. 

3. 

4. 

Q.

In a heated tennis match Nadal returns the ball straight to Federer at 40 m/s speed. Federer returns the ball straight back to Nadal at 30 m/s. Given the mass of ball to be 12 kg, find the impulse with which Federer returned the ball?

1. 35 N

2. 70 N

3. 70 Ns

4. 35 Ns

Q.

In a cricket match, Sachin hit a 1 kg ball thrown at him at 126 km/hr exactly in the opposite direction with the exact same speed. Find the impulse that his bat imparted on the ball in the short duration for which they were in contact.

1. 35 N

2. 35 Ns

3. 70 N

4. 70 Ns

Q.

A cricket ball of mass 150 gm is moving with a velocity of 12 m/s and is hit by a bat so that the ball is turned back with a velocity of 20 m/s. The force of blow acts for 0.01s on the ball. The average force exerted by the bat on the ball is

1. 600 N

2. 500 N

3. 400 N

4. 480 N

Q. A ball moving with a momentum of $5\text{kg m/s}$ strikes against a wall at an angle of 45° and is reflected at the same angle. Calculate the change in momentum (in magnitude).

1. $7.07\text{kg m/s}$
2. $14.04\text{kg m/s}$
3. $3.53\text{kg m/s}$
4. $28.08\text{kg m/s}$

Q. A glass marble whose mass is $200g$, falls from a height of $2.5m$ and rebounds to a height of $1.6m$. Find the impulse acting due to its fall

1. $4.9N-s$
2. $8.8N-s$
3. $2.52N-s$
4. $1.57N-s$

Q. A body of mass $0.05kg$ travelling with a velocity of $5m/s$ make angle of ${30}^0$ with the wall as shown. The body rebounds with the same speed making an angle of ${30}^0$ with the wall. Find the change in momentum of the body.

1. $0.35N-s$
2. $0.50N-s$
3. $0.20N-s$
4. $0.25N-s$

Q. The displacement – time graph of a body of mass $2\text{kg}$ is shown. Find the impulse acting on the body in the time interval $t=2\text{sec}$ to $t=6\text{sec}$

1. $(\sqrt{3}-1)kgm/s$
2. $2(\sqrt{3}-1)kgm/s$
3. $(\sqrt{3}+1)kgm/s$
4. $2\sqrt{3}kgm/s$

Q. Find the total impulse acting on a body up to 8 seconds from the $F-t$ graph shown.

1. $14N$
2. $40N$
3. $20N$
4. $26N$

Q. A metal plate of mass $200\text{gm}$ is balanced in mid – air by throwing 40 balls /sec, each of mass $2\text{gm}$, vertically upwards from below. The balls rebound with the same speed with which they strike the plate. Find the velocity with which the balls strike the plate. (Take $g=9.8m/s^2$)

1. $20\text{m/s}$
2. $12.25\text{m/s}$
3. $10\text{m/s}$
4. $5\text{m/s}$