Question

an object has a velocity of 8 m/s and a kinetic energy of 480 j. what is the mass of the object? (formula: $ke=\frac{1}{2}mv^{2}$) 7.5 kg 120 kg 60 kg 15 kg

Explanation:

Step1: Rearrange the kinetic - energy formula

The kinetic - energy formula is $KE=\frac{1}{2}mv^{2}$. We want to find the mass $m$, so we can rearrange the formula to $m = \frac{2KE}{v^{2}}$.

Step2: Substitute the given values

We are given that $KE = 480\ J$ and $v = 8\ m/s$. Substitute these values into the formula: $m=\frac{2\times480}{8^{2}}$.
First, calculate the denominator: $8^{2}=64$. Then, calculate the numerator: $2\times480 = 960$.
So, $m=\frac{960}{64}=15\ kg$.

Answer:

15 kg