a motorbike has a mass of 300kg, and is being ridden along a straight road. The rider sees a traffic queue ahead. He applies the brakes and reduces the speed of the motorbike from 18m/s to 3 m/s. Use this equation to calculate the kinetic energy lost by the motorbike.
Kinetic energy= 1/2x mass x speed 2.
To calculate the kinetic energy lost by the motorbike, we can use the formula:
Kinetic energy = 1/2 * mass * speed^2
Given:
Mass of the motorbike (m) = 300 kg
Initial speed (u) = 18 m/s
Final speed (v) = 3 m/s
First, we need to find the initial kinetic energy (Ki) and final kinetic energy (Kf) of the motorbike.
Initial kinetic energy (Ki):
Ki = 1/2 * mass * u^2
Substituting the known values:
Ki = 1/2 * 300 kg * (18 m/s)^2
Simplifying:
Ki = 1/2 * 300 kg * 324 m^2/s^2
Ki = 48600 kg m^2/s^2
Final kinetic energy (Kf):
Kf = 1/2 * mass * v^2
Substituting the known values:
Kf = 1/2 * 300 kg * (3 m/s)^2
Simplifying:
Kf = 1/2 * 300 kg * 9 m^2/s^2
Kf = 1350 kg m^2/s^2
Now, to calculate the kinetic energy lost, we subtract the final kinetic energy from the initial kinetic energy:
Kinetic energy lost = Ki - Kf
= 48600 kg m^2/s^2 - 1350 kg m^2/s^2
= 47250 kg m^2/s^2
Therefore, the kinetic energy lost by the motorbike is 47250 kg m^2/s^2.