Question

A car traveling north with a velocity of 30 m/s slows down to a velocity of 10 m/s within 10 seconds. What is the car’s acceleration?

Answer 1

Explanation:

Initial velocity of a car, u = 30 m/s

Final velocity of the car, v = 10 m/s

Time, t = 10 s

To find,

Acceleration of the car.

Solution,

Acceleration of the car is given by the rate of change of its velocity. It is given by the formula as follows :

a= v - u/ t

a= 10 -30 / 10

a=-2 m/s^2

So, the acceleration of the car is 2m/s^2

Answer 2

Explanation:

The car traveled 50 m while accelerating from 0 to 20 m/s in 5 seconds.

The distance d is from

d = v(avg) • t

where v(avg) is the average velocity during the time, or

v(avg) = v(initial) + ∆v/2.

Here v(initial) is 0 and ∆v is 20 m/s, so

v(avg) = 20 m/s / 2 = 10 m/s.

d = 10 m/s • 5 s = 50 m.