Acar skids to a stop. what happens to its kinetic energy?
a) it turns into thermal energy.
b) it disappears without a trace.
c) it turns into potential energy of the tires.
d) nothing: the car still has it, but it is just inactive

a) it turns into thermal energy

Explanation:

Due to the law of energy conservation, an object cannot just "lose" its kinetic energy, it must become another type of energy.

This eliminates option b. because energy of any type cannot disappear.

About option c, we have that the kinetic energy becomes potential energy, but the potential energy of an object is due to its height above the ground, so we cannot have potential energy if the tires are on the floor, we discard option c.

Also, kinetic energy is the energy an object has due to its motion, this means that if the object is not moving, it cannot have kinetic energy.

This eliminates option d.

The correct option is a) it turns into thermal energy.

The option meets the characteristic that the kinetic energy does not disappear, it is transformed into another type of energy. In this case it is thermal energy or heat, generated by friction between the tires and the floor.

he kicked it 10 feet straight up into the air? i think this works.

explanation:

v=uf/(u-f)

= 5.-10/(5+10) convex lens has negative focal length