Question

Bus of mass 4000 kg is moving with a speed of 54 km/h on a level road calculate the force required to stop the bus in a distance of 40 m

Answer 1

Answer:

The force required to stop the bus is 11250 N .

Explanation:

Let , the initial velocity of the bus be u = 54 km/h = 15 m/s

let , the retardation a m/s² is produced upon the bus to stop the bus in a distance of s = 40 meters.

then , the final velocity of the bus will be v = 0

We get , v² = u² - 2as

⇒ 0² = 15² - 2 × a × 40

⇒ a = 15²/( 2 × 40 ) = 2.8125 m/s²

Let the force needed to stop the 4000 kg ( m say ) bus is F N.

Then , from Newton's 2nd law we get ,

F = m × a ⇒ F = ( 4000 × 2.8125 ) = 11250 N