Question

calculating kinetic energy
kevin, whose mass is 80 kg, is moving along at a velocity of 4 m/s. he doubles his velocity by going down a hill. how much kinetic energy does he have after going down the hill?
______ j

Explanation:

Step1: Recall Kinetic Energy Formula

The formula for kinetic energy (KE) is $KE = \frac{1}{2}mv^2$, where $m$ is mass and $v$ is velocity.

Step2: Determine Mass and New Velocity

Given mass $m = 80\ \text{kg}$. Initial velocity $v_1 = 4\ \text{m/s}$, new velocity $v_2 = 2\times4 = 8\ \text{m/s}$.

Step3: Substitute Values into Formula

Substitute $m = 80$ and $v = 8$ into $KE = \frac{1}{2}mv^2$:
$KE = \frac{1}{2} \times 80 \times 8^2$
First, calculate $8^2 = 64$. Then, $\frac{1}{2} \times 80 = 40$. Finally, $40 \times 64 = 2560$.

Answer:

2560