Question

Aqar of mass 2000 kg moving with a speed of 54 km per hour can be stopped by applying brakes after travelling at least 5 metre distance the force applied by brakes is???

Answer 1

Answer:

- 45000 N

Explanation:

Given :

Mass of car ( m ) = 2000 kg

Initial velocity ( u ) = 54 km / hr or 15 m / sec

Distance ( s ) = 5 m

Final velocity ( v ) = 0 m / sec

Now we have third equation of motion :

v² = u² + 2 a s

Putting value here :

0² = 15² + 2 × 5 × a

10 a = - 225

a = - 22.5 m / sec²

Now :

F = m a

F = 2000 ×  - 22.5  N

F = - 45000 N

Since force id vector quality negative sign denotes direction.

Hence we get answer.