$A$ force is applied to a body of mass $3 \ kg$ at rest on a frictionless horizontal surface, as shown in the force-time $(F-t)$ graph. The speed of the body after $1 \ s$ is: (in $m/s$)

$A$ body of mass $2 \,kg$ collides with a wall with a speed of $100 \,ms^{-1}$ and rebounds with the same speed. If the time of contact is $1/50 \,s$,the force exerted on the wall is

$A$ ball of mass $0.5\, kg$ moving with a velocity of $2\, m/s$ strikes a wall normally and bounces back with the same speed. If the time of contact between the ball and the wall is $1\, ms$,the average force exerted by the wall on the ball is ......... $N$.

In two different experiments,an object of mass $5 \; kg$ moving with a speed of $25 \; ms^{-1}$ hits two different walls and comes to rest within
$(i)$ $3 \; s$,$(ii)$ $5 \; s$,respectively.
Choose the correct option out of the following:

When the speed of a moving body is doubled:

$A$ ball of mass $3 \ kg$,moving with a speed of $100 \ m/s$,strikes a wall at an angle of $60^{\circ}$ with the wall (as shown in the figure). The ball rebounds at the same speed and remains in contact with the wall for $0.2 \ s$. The force exerted by the ball on the wall is: