6. An object accelerates from rest to 70 m/s in 3.5 s. What is the acceleration of the object?

The acceleration of the object is 20 meters per second square = 20 m/s^2

Explanation:

Recall that acceleration is defined as the change in velocity divided the time it takes for the change. Therefore , if the object accelerates from rest (zero velocity) to 70 m/s , the change in velocity is (70 m/s - 0 m/s = 70 m/s)

which divided by the 3.5 seconds it took for the change, gives:

acceleration = (70 m/s  /  3.5 s ) = 20  m/s^2

see earlier