Question

the speed of a car is decreasing uniformly from 35 m/s to 15 m/s in 4 s the magnitude of the car's acceleration is

Answer 1

Answer:

-5m/s²

Explanation:

Acceleration is defined as the change of velocity of a body with respect to time. Mathematically;

Acceleration a = change in velocity/time t

Where change in velocity = final velocity v - initial velocity u

acceleration a = final velocity v - initial velocity u/time t

a = v-u/t

If the speed of a car is decreasing uniformly from 35 m/s to 15 m/s in 4s then;

Initial velocity of the car = 35m/s

Final velocity of the car = 15m/s

Time taken = 4s

Substituting this datas in the formula, we can get the acceleration of the car;

Acceleration = 15-35/4

Acceleration = -20/4

Acceleration = -5m/s²

Negative acceleration shows that the car is decelerating

Answer 2

Initial speed = 35m/s, final speed = 15m/s. Acceleration = final velocity - initial velocity/ total time = 15-35/4 = -20/4 = -5m/s^2. Therefore magnitude of acceleration is 5m/s^2.