Question

a soccer ball is traveling at a velocity of 50 m/s. the kinetic energy of the ball is 500 j. what is the mass of the soccer ball? (formula: $ke=\frac{1}{2}mv^{2}$)
o 0.1 kg
o 0.2 kg
o 0.4 kg
o 0.5 kg

Explanation:

Step1: Rearrange kinetic - energy formula

Given $KE=\frac{1}{2}mv^{2}$, we can solve for $m$. Multiply both sides by 2 to get $2KE = mv^{2}$, then $m=\frac{2KE}{v^{2}}$.

Step2: Substitute given values

We know that $KE = 500\ J$ and $v = 50\ m/s$. Substitute these values into the formula: $m=\frac{2\times500}{50^{2}}$.
First, calculate $50^{2}=2500$, and $2\times500 = 1000$. Then $m=\frac{1000}{2500}=0.4\ kg$.

Answer:

0.4 kg