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.

5 m/s

12.5 J

25 J

50 m/s

Answer 1

To calculate the velocity of the ball as it was launched, we can use the formula for kinetic energy:

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

Where:
- \( KE \) is the kinetic energy (25 J in this case),
- \( m \) is the mass of the ball (2 kg),
- \( v \) is the velocity we want to find.

We can rearrange the formula to solve for \( v \):

\[
v = \sqrt{\frac{2 \times KE}{m}}
\]

Substituting the known values:

\[
v = \sqrt{\frac{2 \times 25 \, \text{J}}{2 \, \text{kg}}}
\]

\[
v = \sqrt{\frac{50}{2}}
\]

\[
v = \sqrt{25}
\]

\[
v = 5 \, \text{m/s}
\]

Therefore, the velocity of the ball as it was launched is **5 m/s**.