9. Work & Energy

Which requires more work on the brakes of a car: bringing a car traveling at $60\mathrm{km}/h$ to a stop, or bringing the same car traveling at $30\mathrm{km}/h$ to a stop?

When water at the top of a waterfall falls to the bottom, what type of energy is the $\mathrm{kinetic}\mathrm{energy}$ of the water transformed into?

A particle of mass $m$ has a final kinetic energy $K{f}_{}$. What is the final speed of the particle? Express your answer in terms of $K{f}_{}$ and $m$.

Which of the following best describes how $\mathrm{electrical} \mathrm{energy}$ is commonly produced from $\mathrm{potential} \mathrm{energy}$ and $\mathrm{kinetic} \mathrm{energy}$ in a power plant?

Which of the following best describes the relationship between $\mathrm{kinetic energy}$ and $\mathrm{potential energy}$ in a closed system with no energy loss?

Which of the following statements is true in the limit of large kinetic energy (that is, as $K>0$ and $K$ becomes much larger than the rest energy $E_{\text{rest}}$) for a particle moving at relativistic speeds?

How does $kinetic energy$ differ from $potential energy$?

Which of the following best describes two ways engineers use their understanding of kinetic energy $\mathrm{KE}$ and potential energy $\mathrm{PE}$ to improve the safety and effectiveness of their designs?

Which of the following is a form of mechanical energy?

What is the potential energy stored in a spring with a spring constant of $100N/m$ when it is compressed by $0.1m$?

Which of the following best describes energy changes in a closed system?$E$

$What\; type\; of\; energy\; includes\; both\mathrm{kinetic}and\mathrm{potential}energy?$

In the context of energy and motion, what does the symbol $g_0$ represent?

A $2\mathrm{kg}$ cart is moving at $4m/s$ on a frictionless track and starts to coast up a hill. How far up the hill will it coast before coming to rest and starting to roll back down, if the hill makes an angle of $30°$ with the horizontal? (Assume $g=9.8m/s^2$)

Which of the following best describes $\mathrm{energy}$?