Question

A car is travelling at a speed of 10m/s brought to a rest in 20s by applying brakes .calculate acceleration and distance

Answer 1

Answer:

Acceleration = -0.5 m/s²

Distance = 100 metres

Explanation:

Given:

• Initial velocity = u = 10 m/s

• Final velocity = v = 0 m/s (As the car would finally come to rest)
• Time = 20 seconds

To find:

• Acceleration of the car
• Distance covered by the car

Using first equation of motion:

V=u+at

0=10+a×20

0=10+20a

-10=20a

a = -10/20

a = -0.5 m/s²

Using the second equation of motion:

S=ut+$\frac{1}{2}$at²

S=10×20+$\dfrac{1}{2}$×-0.5×400

S=200-100

S=100 metres

The distance covered by the car is equal to 100 metres