9. Work & Energy

A frictionless roller coaster car of mass $m$ starts from rest at a height $h$ above the ground. What is the speed of the car when it reaches the bottom of the track, assuming no energy is lost to friction or air resistance?

What type of energy transformation occurs when a light bulb is turned on?

Which energy transformation primarily occurs in an $AC$ motor during its operation?

Which of the following activities uses the most amount of $\mathrm{kinetic} \mathrm{energy}$?

When the switch in (figure 1) has been open for a long time and is closed at $t=0s$, which of the following best describes the initial behavior of the current through the inductor in the circuit?

When a moving car collides with a parked car, which of the following best describes what happens to the $kinetic energy$ of the system?

A space explorer is falling freely towards the surface of a planet. To survive the impact, the explorer must not exceed a maximum kinetic energy of $K_{\max }$ at the moment of landing. If the explorer has a mass $m$, what is the minimum speed the rocket must provide just before impact (relative to the ground) to ensure the explorer's kinetic energy does not exceed $K_{\max }$?

Which of the following best describes the relationship between the speed of an object and its kinetic energy?

Which energy conversion do wind turbines primarily take advantage of?

Which of the following scenarios best illustrates $\mathrm{kinetic} \mathrm{energy}$ in everyday life?

$\text{Which of the following is considered a type of potential energy?}$

Which two factors directly determine the $\mathrm{kinetic} \mathrm{energy}$ of an object?

What is the standard SI unit of measurement for work?

What is the source of almost all energy on $Earth$?

In the context of energy flow in a system, which of the following is typically the initial source of $E$?