A skydiver jumps out of a plane and begins to accelerate. His speed increases to 20 m/s, then 30 m/s. His acceleration slows until he reaches a constant speed of 50 m/s. Which statement accurately describes his kinetic energy while falling?(1 point)

Question

Responses

His kinetic energy increased quickly at first, then it increased at a constant rate.
His kinetic energy increased quickly at first, then it increased at a constant rate.

His kinetic energy would remain the same for the whole fall as long as he lost no mass.
His kinetic energy would remain the same for the whole fall as long as he lost no mass.

His kinetic energy increased while his speed increases, then it became constant.
His kinetic energy increased while his speed increases, then it became constant.

His kinetic energy was positive at first, but it decreased to zero when he stopped accelerating.

Answer 1

To determine which statement accurately describes the kinetic energy of the skydiver, we need to consider how kinetic energy is calculated. Kinetic energy (KE) is given by the formula:

\[ KE = \frac{1}{2}mv^2 \]

where \(m\) is the mass of the object and \(v\) is its velocity.

As the skydiver accelerates and his speed increases from 0 m/s to 20 m/s and then to 30 m/s, his kinetic energy also increases, since both the mass and the square of the speed are positive values.

When he reaches a constant speed of 50 m/s, his kinetic energy stabilizes at that speed, meaning it does not increase further as long as he maintains that constant speed.

Thus, the statement that best describes the kinetic energy of the skydiver is:

His kinetic energy increased while his speed increases, then it became constant.