Question

Marcel is performing the first test on his company's new electric car. During the test, the electric car reaches a maximum speed of 81 mph.

The performance test results of the electric car can be modeled by the following table, where x represents time, in seconds at the start of the test, and y represents the speed, in miles per hour.

x 0 2 4 6 8 10 12
y 0 45 72 81 72 45 0

Which of the following statements is true about this situation?

A.
The electric car is not moving at 0 seconds and 6 seconds.
B.
The electric car is not moving at 6 seconds and 12 seconds.
C.
The electric car is not moving at 0 seconds and 12 seconds.
D.
The electric car is not moving at 4 seconds and 8 seconds.

Answer 1

Explanation:

C.-

Answer 2

C. The electric car is not moving at 0 seconds and 12 seconds.

Explanation:

Given:

The table given is:

x 0 2 4 6 8 10 12

y 0 45 72 81 72 45 0

From the above table, we observe that the car starts from rest and its speed increases from 0 to 6 seconds, the maximum speed being 81 mph.

After 6 seconds, the speed of the car goes on decreasing till it stops at time equal to 12 seconds.

So, the speed of the car at the start when
`x=0` is 0 mph as it is at rest at that time.

Also, when the time is
`x=12\ s`, the car has come to a stop and thus its speed has reduced to 0 mph again. So, the car is not moving after 12 seconds.

From the above conclusion, we can say that only option C is correct.

The electric car is not moving at 0 seconds and 12 seconds.