The car starts moving in a straight line from a state of rest with an acceleration of 0.2 m / s2.

The car starts moving in a straight line from a state of rest with an acceleration of 0.2 m / s2. How long does it take for it to acquire a speed of 20m / s?

Since the car starts moving from a state of rest in a straight line, its initial speed was v₀ = 0 m / s.

From the condition of the problem it is known that the acceleration of the car was a = 0.2 m / s ^ 2.

To determine how long it takes for it to acquire a velocity v = 20 m / s, we will use the definition of acceleration:

a = (v – v₀): t, then,

t = (v – v₀): a.

Substitute the values of physical quantities in the calculation formula:

t = (20 m / s – 0 m / s): 0.2 m / s ^ 2;

t = 100 s.

Answer: in 100 seconds the car will acquire the required speed.