Question

A. a car starts from rest and reaches a velocity of 6.4 m/s in 2.5 seconds. whats the accelaration of the car. b. the car travels at a constant speed of 6.4 seconds for next 5 mins. what is the accelaration of the car​

Answer 1

Given: A car starts from rest and reaches velocity 6.4 m/s in 2.5 s. It then travels at constant speed of 6.4 s for next 5 minutes.

To find: Acceleration of car in both cases

Explanation: In the first case, the car starts from rest. Therefore, initial velocity= 0

Final velocity= 6.4 m/s

Time= 2.5 s

Let acceleration be a.

Using kinematics formula, v= u+ at

=> a = 6.4/2.5

= 2.56 m/s^2

In second case, the car moves with constant velocity= 6.4 m/s.

Any body that moves with constant velocity over a period of time has zero acceleration.

Therefore, a= 0 in this case.

Therefore, the acceleration in first case is 2.56 m/s^2 and acceleration in second case is 0.