Question

Calculate the work done required to be done to stop a car of 1500kg moving at a velocity of 60km/hrs

Answer 1

Hey Pretty Stranger!

When a moving car stops, its kinetic energy becomes zero. So, the work required to be done to stop the moving car will be equal to the kinetic energy possessed by the moving car. This can be calculated as :

• Mass of the car, m = 1500 kg

• Velocity of the car, v = 60 km/h

We hafta change that km/h into m/s and that'd be

$\rightarrow \: \sf \: \dfrac{60 \times 1000}{60 \times 60} \: m {s}^{ - 1}$

$\rightarrow \: \sf \: \dfrac{50}{3} \: m {s}^{ - 1}$

Now,

$\bigstar \: \boxed{ \sf \: Kinetic \: Energy = \frac{1}{2} m {v}^{2}}$

$\longrightarrow \: \sf \: \dfrac{1}{2} \times 1500 \times ( \dfrac{50}{3} )^{2}$

$\longrightarrow \: \sf \cancel \dfrac{3750000}{18}$

$\longrightarrow \: \sf 208333.3 \: J$

$\therefore$ 208333.3 Joules of work has to be done to stop this moving car.