Question

question 25 1 pts a circus diver drops from a high pole into water far below. when he is halfway down his kinetic energy and potential energy are equal. his potential energy is halved. he has gained an amount of kinetic energy equal to half his initial potential energy. all of the above none of the above

Explanation:

Step1: Recall energy - conservation principle

The initial mechanical energy of the diver is only potential energy, given by $U = mgh$, where $m$ is the mass, $g$ is the acceleration due to gravity, and $h$ is the initial height.

Step2: Analyze at halfway - down position

When the diver is halfway down ($h'=\frac{h}{2}$), the potential energy is $U'=mg\frac{h}{2}$, which is half of the initial potential energy. According to the conservation of mechanical energy ($E = U+K$ and in the absence of non - conservative forces, $E$ is constant), the initial energy $E = mgh$ and at halfway down $E = U'+K'=mg\frac{h}{2}+K'$. Since $E = mgh$, then $K'=mg\frac{h}{2}$, which means the kinetic energy is equal to the potential energy at this point, and also the kinetic energy gained is equal to half of the initial potential energy.

Answer:

D. all of the above