Question

a car of mass 80 kg is moving at the speed of 36 km per hour is stopped by applying brakes in 10 second calculate the force applied by the brakes​

Answer 1

Answer:

Mass of the car = 80 kg

Speed of the car = 36 km/hr = 36×5/18 = 10 m/s

Time = 10 s

Force applied by the brakes ?

Let is firstly find the acceleration of the body.

Acceleration = v - u/t = 10 - 0/10 = 10/10 = 1 m/s²

Now, We know that : Force = Mass × Acceleration = 80 × 1 = 80 N.

Therefore, the force exerted by the brakes : 80 N.

Some helpful formulas and definitions :

• Acceleration = v - u/t
• v = u + at
• s = ut + ½at²
• v² - u² = 2as
• Relative velocity = v_B - v_A
• Force = Mass × Acceleration
• Instantaneous velocity = dx/dt
• Average Displacement = ∆x/∆t
• Instantaneous Acceleration = dv/dt