Question

While Calvin is doing a physics experiment outside with a radar gun, he notices that after three seconds a car reaches a speed of 20 m/s while accelerating at 3 m/s squared. what was the initial velocity of the car?

Answer 1

The initial velocity of the car is 11 m/s.

Explanation:

• Here, we can use the equations of motions.
• The first of equation of motion is v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time.

• The given parameters are,

Final velocity, v = 20 m/s

acceleration of the care, a = 2 m/$s^{2}$

time, t = 3 s

Initial velocity, u = ?

• Hence, the equation can be written as u = v - at

once you substitute all these vales, you will get u = 11 m/s