Calculate the work required to be done to stop a car of 1500 kg moving

1.	Calculate the work required to be done to stop a car of 1500 kg moving at the velocity of 60km/h?
Answer» Mass, m = 1500 kg. Initial velocity, u = 60 kmh^-1 = 60 × \(\frac{5}{18}\) = 16.67 ms^-1 Final velocity, v = 0 (∵ the car comes to rest) Work done to stop the car = change in kinetic energy = Final kinetic energy – Initial Kinetic energy = \(\frac{1}{2}\)mv² - \(\frac{1}{2}\)mu² = \(\frac{1}{2}\) x 1500 x (0)² - \(\frac{1}{2}\) x 1500 x (16.67)² = \(\frac{1}{2}\) x 1500 x (16.67)² = 208333.331 J

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

Answer»

Mass, m = 1500 kg.

Initial velocity, u = 60 kmh^-1

= 60 × \(\frac{5}{18}\) = 16.67 ms^-1

Final velocity, v = 0

(∵ the car comes to rest)

Work done to stop the car = change in kinetic energy

= Final kinetic energy – Initial Kinetic energy

= \(\frac{1}{2}\)mv² - \(\frac{1}{2}\)mu²

= \(\frac{1}{2}\) x 1500 x (0)² - \(\frac{1}{2}\) x 1500 x (16.67)²

= \(\frac{1}{2}\) x 1500 x (16.67)²

= 208333.331 J