As you drive in your car at 22.5 mi/h, you see a child’s ball roll into the street ahead of you. You hit the brakes and stop as quickly as you can. In this case, you come to rest in 2 s. How far does your car travel as you brake to a stop? (Use: 1 mile= 1600 m, 1 h= 3600s)

Explanation:

Speed of car =22.5miles/hr

U=22.5miles/hour

Applied brake and come to rest

Final velocity, =0

t, =2sec

Given that,

Speed=distance /time

Then,

Distance, =speed, ×time

Converting mile/hour to m/s

Given that

Use: 1 mile= 1600 m, 1 h= 3600s

22.5miles/hour × 1600m/mile × 1hour/3600s

Therefore, 22.5mile/hour=10m/s

Using speed =10m/s

Distance =speed ×time

Distance=10×2

Distance, =20m

The distance travelled before coming to rest is 20m.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.