Question

400 kg truck is moving with a velocity 40 kilometre per hour it is top 25 Metro beyond the point at which the brakes are applied find the retarding force​

Answer 1

Correct Question :-

• A truck of mass 400 kg is moving with a velocity of 40 km/h. If on applying brakes, the truck stops after coming to a distance of 25 m, find the retarding force?

Given :-

• Mass = m = 400 kg
• Initial Velocity = u = 40 km/h
• Final velocity = v = 0 ( Since it will come at rest )
• Distance = s = 25 m

To Find :-

• Retarding force = ?

Solution :-

3rd Equation of motion :-

⇾  v² - u² = 2as

⇾  0² - 40² = 2 × a × 25

⇾  -1600 = 50a

⇾  a = 1600/50

⇾  a = -32 m²

Hence distance covered is -32 m².

Now,

➲  Force = Mass × Acceleration

➲  F = 400 × -32

➲  F = -12800 N

▪️Negative sign shows force against direction of motion.

Hence,

Retarding force = 12800 N  ☑