While decreasing linearly from $5 \mathrm{N}$ to $3 \mathrm{N}$, a force displaces an object from $3 \mathrm{m}$ to $5 \mathrm{m}$. Calculate the work done by this force during this displacement.

A ball of mass $100 \mathrm{g}$ dropped on the ground from $5 \mathrm{m}$ bounces repeatedly. During every bounce $64\%$ of the potential energy is converted into kinetic energy. Calculate the following: 

(b) Speed with which the ball comes up from the ground after third bounce.

A ball of mass $100 \mathrm{g}$ dropped on the ground from$5 \mathrm{m}$ bounces repeatedly. During every bounce $64\%$ of the potential energy is converted into kinetic energy. Calculate the impulse(magnitude) given by the ball to the ground during this bounce in $\mathrm{kg} \mathrm{m} {\mathrm{s}}^{-1}$.

A ball of mass $100 \mathrm{g}$ undefined dropped on the ground from $5 \mathrm{m}$ undefined bounces repeatedly. During every bounce $64\%$ undefined of the potential energy is converted into kinetic energy. Calculate the following:

(d) Average force exerted by the ground if this impact lasts for $250 \mathrm{ms}.$

A ball of mass $100 \mathrm{g}$ dropped on the ground from $5 \mathrm{m}$ bounces repeatedly. During every bounce $64\%$ of the potential energy is converted into kinetic energy. The average pressure exerted by the ball on the ground during this impact if contact area of the ball is $0.5 {\mathrm{cm}}^2$ is $9.12\times {10}^k \mathrm{N}/{\mathrm{m}}^2$. What is the value of $k$?