Question

a 2 kg ball is launched upward and has a kinetic energy of 25 j. solve for the velocity of the ball as it was launched. (1 point)

12.5 j

50 m/s

25 j

5 m/s

Explanation:

Step1: Recall kinetic - energy formula

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

Step2: Rearrange the formula for velocity

Starting from $K=\frac{1}{2}mv^{2}$, we can solve for $v$. First, multiply both sides by 2 to get $2K = mv^{2}$. Then, divide both sides by $m$: $v^{2}=\frac{2K}{m}$. Finally, take the square - root of both sides: $v=\sqrt{\frac{2K}{m}}$.

Step3: Substitute given values

We are given that $K = 25\ J$ and $m = 2\ kg$. Substituting these values into the formula $v=\sqrt{\frac{2K}{m}}$, we have $v=\sqrt{\frac{2\times25}{2}}=\sqrt{25}=5\ m/s$.

Answer:

D. 5 m/s