9. Work & Energy

Which scenario requires the most work to move a box of mass $m$ up a frictionless inclined plane to a height $h$ above the ground?

Which of the following best explains how a pulley does work when lifting a mass up an inclined plane?

A block of mass $m$ is pulled up a frictionless inclined plane of angle $\theta$ by a constant force $F$ parallel to the incline, moving it a distance $d$ along the plane. How much work is done by the force $F$ on the block during this displacement?

A $100 \mathrm{lb}$ rock is lifted vertically to a height of $3 \mathrm{ft}$. How much work is done against gravity in this process?

When you push an object a certain distance while applying twice the force, you do which of the following to the work done compared to using the original force over the same distance? $W=Fd$, so if $F$ doubles and $d$ stays the same, $W$ doubles.

Which of the following situations involves work being done on an object on an inclined plane?

On an inclined plane, mechanical advantage is the ratio of $\frac{\mathrm{output}\mathrm{force}}{\mathrm{input}\mathrm{force}}$, while efficiency is the ratio of $\frac{\mathrm{work}\mathrm{output}}{\mathrm{work}\mathrm{input}}$ expressed as a percentage. Which of the following correctly defines mechanical advantage and efficiency for an inclined plane?

A flea of mass $m$ jumps up an inclined plane making an angle $\theta$ with the horizontal, reaching a vertical height $h$ in time $t$. Assuming no friction and using $g=10m/s^2$, how much work did the flea do during that time?

Which of the following situations best illustrates work being done on an object on an inclined plane?

A block with a weight of $5000N$ is lifted vertically upward a distance of $10m$. How much work is done on the block by the lifting force?

When a block is pulled up a frictionless inclined plane by a rope at constant speed, is the work done by the tension force positive, negative, or zero?