Question

a truck of mass 200kg moving with speed 54km/hr after applying break it stop & cover 100m.find force execterd by truck​

Answer 1

Given:-

→ Mass of the truck = 200kg

→ Initial speed of the truck = 54km/h

→ Distance covered = 100m

To find:-

→ Force exerted by the truck

Solution:-

Firstly, let's convert the initial speed of the car from km/h to m/s.

=> 1km/h = 5/18m/s

=> 54km/h = 5/18×54

=> 15m/s

In this case :-

• Final speed of the truck will be zero as it will finally come to rest after application of brakes.

Let's calculate the acceleration of the truck by using the 3rd equation of motion.

=> v² - u² = 2as

=> 0 - (15)² = 2×a×100

=> -225 = 200a

=> a = -225/200

=> a = -1.125m/s²

Now, let's calculate the magnitude of force by using the 2nd law of motion.

=> F = ma

=> F = 200(-1.125)

=> F = -225 N

[ Here, -ve sign represents retarding force ]

Thus, the force exerted by the truck is -225 N or a retarding force of 225 N.