Question

A car is moving northeast at a velocity of 10 meters per second. Four

seconds later it's going 30 meters per second. What was the car's average
acceleration during this time?

A) 5 m/s
B) 5 m/s²
C) 5 m/s² Northeast
D) 20 m/s² Northeast ​

Answer 1

The average acceleration of car during this time is 5
`m/s^2` Northeast.

Answer: Option C

Step-by-step explanation:

The acceleration exerted by an object is the rate of change in velocity the object undergoes with respect to time. Average acceleration is the measure of variation in acceleration in a given interval of time.

`\text {Average acceleration}=\frac{\text {Final velocity - Initial velocity}}{\text {Time Period}}`

Here, final velocity is 30 m/s and initial velocity is 10 m/s. The final velocity is attained by the car after 4 s. Thus, the average acceleration will be

`\text {Average acceleration}=(30-10)/(4)=(20)/(4)=5 \frac{\mathrm{m}}{\mathrm{s}^(2)}`

So, the average acceleration is 5
`m/s^2` and as the car was moving in the northeast direction, the average acceleration will also be exerting in the northeast direction only.