A $4 \mathrm{kg}$ mass moving with speed $2 \mathrm{m} {\mathrm{s}}^{–1},$ and a $2 \mathrm{kg}$ mass moving with a speed of $4 \mathrm{m} {\mathrm{s}}^{–1},$ are gliding over a horizontal frictionless surface. Both objects encounter the same horizontal force, which directly opposes their motion, and are brought to rest by it. Which statement best describes their respective stopping distances?

A particle is moved from $\left(0, 0\right)$ to $\left(a, a\right)$ under a force $\overrightarrow{F}=\left(3\hat{\mathrm{i}}+4\hat{\mathrm{j}}\right)$ from two paths. Path $1$ is $OP$ and path $2$ is $OQP$. Let $W_1$ and $W_2$ be the work done by this force in these two paths. Then

The $300 \mathrm{N}$ crate slides down the inclined curved path from $A$ to $B$ in the vertical plane as shown in the figure. If the crate has a velocity of $1.2 \mathrm{m} {\mathrm{s}}^{–1}$ down the inclined at point $A$ and $8 \mathrm{m} {\mathrm{s}}^{–1}$ at $B.$ Find the work done against friction during the motion.