Question

question 12 of 25
a car with mass 450 kg has a kinetic energy of 16,256 j. what is the speed of
the car?
a. 11.2 m/s
b. 5.9 m/s
c. 8.5 m/s
d. 1.2 m/s

Explanation:

Step1: Write the 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 speed. We need to solve for \(v\). Rearranging the formula for \(v\) gives \(v=\sqrt{\frac{2K}{m}}\).

Step2: Substitute the given values

Given \(K = 16256\space J\) and \(m = 450\space kg\). Substitute these into the formula: \(v=\sqrt{\frac{2\times16256}{450}}\).
First, calculate the numerator \(2\times16256 = 32512\). Then \(\frac{32512}{450}\approx72.25\).

Step3: Calculate the square - root

\(v=\sqrt{72.25}\approx 8.5\space m/s\)

Answer:

C. \(8.5\space m/s\)