9. Work & Energy

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?

A block of mass $m$ is pulled up a frictionless inclined plane of angle $\theta$ by a force $F$ applied parallel to the incline, moving the block a distance $d$ along the incline. Considering the three forces acting on the block (applied force, gravity, and the normal force), how much work is done by each force during the displacement?

If a motor does work $W$ to move a platform up an inclined plane at constant speed and delivers power $P$, how much time $t$ does it take for the motor to complete this work?

When an object moves up an inclined plane, how does the work done by an external force affect the object's energy?

A block of mass $m$ is pushed up a frictionless inclined plane of length $L$ and angle $\theta$ with respect to the horizontal. How much work is required to move the block from the bottom to the top of the incline?

A supertanker of mass $m$ is pulled a distance $d$ along a straight, frictionless channel by two tugboats. Each tugboat exerts a constant force of magnitude $F$ at an angle $\theta$ above the direction of motion. What is the total work done by the two tugboats on the supertanker?

If $2$ times as much work is done on a body moving up a frictionless inclined plane, what happens to the change in the body's energy?

A $50\mathrm{kg}$ compressor is pulled up a frictionless inclined plane that makes an angle of $30°$ with the horizontal. If the compressor is displaced $5m$ along the incline, how much work does gravity do on the compressor during this displacement?

How much work is required to lift an object with a mass of $5.0$ kilograms to a height of $3.5$ meters against gravity? (Assume $g=9.8m/s^2$)

A box of mass $m$ slides down a frictionless inclined plane of length $L$ and angle $\theta$ with respect to the horizontal. What is the work $W_g$ done on the box by gravity as it moves from the top to the bottom of the incline?

A $1.3$ kg remote-controlled car moves along an inclined plane, and its velocity is plotted as a function of time. If during segment A of the graph the car's velocity increases from $2$ m/s to $5$ m/s, what is the work done on the car during segment A in joules?

Which of the following scenarios on an inclined plane best illustrates a case where no work is done by the applied force on the object?$W=F\cdot d\cdot cos\left(\theta \right)$