Question

A car initially traveling west at 30 m/s for 10-seconds applies the brakes from 10-20s over a distance of 175m. Afterwards, the car continues moving forward at a constant velocity.

A. Calculate your he acceleration of the car from 10-20s.

B. Calculate the final speed of the car after it decelerates.

Answer 1

A. 2.5 m/s²

B. 5 m/s

Step-by-step explanation:

A. Given in the west direction:

s = 175 m

u = 30 m/s

t = 20−10 = 10 s

Find: a

s = ut + ½ at²

175 = (30)(10) + ½ a (10)²

a = -2.5

The deceleration of the car is 2.5 m/s².

B. Find: v

s = ½ (u + v) t

175 = ½ (30 + v) (10)

v = 5

The final speed is 5 m/s.