Question

2.1.2 quiz: types of energy
question 2 of 10
a car with a mass of 2,000 kg travels a distance of 400 m as it moves from one stoplight to the next. at its fastest, the car travels at 18 m/s. what is its kinetic energy at this point?

a. 324,000 j
b. 1,620 j
c. 18,000 j
d. 648,000 j

Explanation:

Step1: Recall kinetic energy formula

The formula for kinetic energy ($KE$) is $KE = \frac{1}{2}mv^2$, where $m$ is mass and $v$ is velocity.

Step2: Identify given values

Mass $m = 2000\ kg$, velocity $v = 18\ m/s$.

Step3: Substitute values into formula

Substitute $m = 2000$ and $v = 18$ into $KE=\frac{1}{2}mv^2$:
$$KE=\frac{1}{2}\times2000\times(18)^2$$
First, calculate $(18)^2 = 324$. Then, $\frac{1}{2}\times2000 = 1000$. Now multiply $1000\times324 = 324000$.

Answer:

A. 324,000 J