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?

A cubic meter of water (density $\rho$ = $1000$ kg/$m^3$) falls vertically down the Cherun-Meru waterfall, which has a height of $350$ m. How much work does gravity do on the water during its fall? (Assume $g$ = $9.8$ m/$s^2$ and neglect air resistance.)

If the net work done on an object is positive as it moves up an inclined plane, which of the following statements is true about the object's motion?

A block of mass $m$ is pulled up a frictionless inclined plane of length $L$ and angle $\theta$ with respect to the horizontal. How much work must be done by an external force to move the block from the bottom to the top of the incline if the vertical height gained is $h$?

Which of the following is occurring when $W=F\cdot d$ (work) is being done on an object moving up an inclined plane?