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:

Mass of the car: 2000 kg

Speed of the car = 54 km/hr = 15 m/s

Distance Traveled after applying brakes : 5 m

Force applied by brakes = ?

Let's find acceleration first. Using Third Equation of Motion we get,

⇒ v² - u² = 2as

⇒ 0² - 15² = 2 ( -a ) ( 5 )  

Negative sign indicates retardation

⇒ -225 = -10a

⇒ a = 225/10 = 22.5 m/s²

Force = Mass × Acceleration

⇒ Force = 2000 kg × 22.5 m/s²

⇒ Force = 45000 N

Therefore Force applied by the brakes is 45,000 N.

Answer 2

Answer:

45 KN

Explanation:

54 km per hour = 54 x 1000/3600 = 15m/s

a = v²/2s = 15²/10 = 22.5 m/s²

F = ma = 2000x22.5 = 45000 N = 45 KN