Question

a 20 kg dog has 250 j of kinetic energy as it chases after a cat. the dogs velocity is ____________. (1 point)

25 m/s

250 m/s

12.5 m/s

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. We need to solve for $v$.

Step2: Rearrange the formula for $v$

Starting from $K=\frac{1}{2}mv^{2}$, we 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 know that $K = 250\ J$ and $m = 20\ kg$. Substitute these values into the formula: $v=\sqrt{\frac{2\times250}{20}}=\sqrt{\frac{500}{20}}=\sqrt{25}$.

Step4: Calculate the value of $v$

$\sqrt{25}=5\ m/s$.

Answer:

$5\ m/s$