Question

A car starts from rest and accelerates along a straight line path in one minute. It finally attains a velocity of 40 meters/second. What is the car's average acceleration?

a. 1.5 meters/second^2
b. 1.5 meters/second
c. 0.66 meters/second^2
d. 0.66 meters/second

Answer 1

Answer: The correct answer is 0.66 meters/second^2.

Step-by-step explanation:

The expression for the acceleration is as follows:

`a= (v-u)/(t)`

Here, a is the acceleration, v is the final velocity and u is the initial velocity.

It is given in the problem that A car starts from rest and accelerates along a straight line path in one minute. It finally attains a velocity of 40 meters/second.

The time taken by a car is time, t= 1 min = 60 s.

Calculate the car's average acceleration.

Put t= 60 s, u= 0 and v= 40 m/s in the above expression.

`a= (40-0)/(60)`

`a=0.66 meters/second^2`

Therefore, the correct option is (c).

Answer 2

The average acceleration of the car is given by:

`a= (v_f-v_i)/(t)`
where
`v_i` is the initial velocity of the car,
`v_f` is its final velocity and t is the time taken to attain the final speed. The car in the problem starts from rest, therefore its initial velocity is zero:
`v_i=0`. The final velocity is
`v_f=40 m/s`, while the time taken is

`t=1 min= 60 s`
Therefore, the average acceleration of the car is

`a= (40)/(60) =0.66 m/s^2`
and the correct answer is C.