$A$ boy hits a baseball with a bat and imparts an impulse $J$ to the ball. The boy hits the ball again with the same force,except that the ball and the bat are in contact for twice the amount of time as in the first hit. The new impulse equals:

$A$ particle of mass $2 \ kg$ is initially at rest. $A$ force acts on it whose magnitude changes with time. The force-time graph is shown below. The velocity of the particle after $10 \ s$ is $.... \ ms^{-1}$.

Figures $(a)$,$(b)$,$(c)$ and $(d)$ show the variation of force with time. The impulse is highest in which figure?

$A$ bob of mass $10m$ is suspended through an inextensible string of length $l$. When the bob is at rest at the equilibrium position, two particles of mass $m$ each, moving with velocity $u$, strike the bob at an angle of $60^{\circ}$ with the string and get simultaneously attached to it. What is the value of the impulsive tension $J$ in the string during the impact?

$A$ $100 \, g$ iron ball having a velocity of $10 \, m/s$ collides with a wall at an angle of $30^\circ$ with the wall surface and rebounds with the same angle. If the period of contact between the ball and the wall is $0.1 \, s$,then the force experienced by the ball is ............. $N$.

Which parameter is used to determine the effect of force on a body?