First 72-36 = 36
second km/h converted into m/s
then use kinetic energy formula
Ek=1/2mv^2
and get your answer

Calculation of Increase in Kinetic Energy

Given:
Mass of the vehicle (m) = 500 kg
Initial speed (u) = 36 km/h
Final speed (v) = 72 km/h

To calculate the increase in kinetic energy, we need to find the difference between the final kinetic energy and the initial kinetic energy.

Step 1: Convert speed from km/h to m/s

To ensure that all the units are consistent, we need to convert the speeds from km/h to m/s. We can do this by multiplying the values by 1000/3600 (since 1 km = 1000 m and 1 hour = 3600 s).

Initial speed (u) = 36 km/h = (36 × 1000) / 3600 m/s = 10 m/s
Final speed (v) = 72 km/h = (72 × 1000) / 3600 m/s = 20 m/s

Step 2: Calculate the initial kinetic energy (KEi)

The formula to calculate kinetic energy is KE = 0.5 × mass × speed^2.

Initial kinetic energy (KEi) = 0.5 × mass × initial speed^2
= 0.5 × 500 × 10^2
= 0.5 × 500 × 100
= 25,000 J

Step 3: Calculate the final kinetic energy (KEf)

Final kinetic energy (KEf) = 0.5 × mass × final speed^2
= 0.5 × 500 × 20^2
= 0.5 × 500 × 400
= 40,000 J

Step 4: Calculate the increase in kinetic energy

Increase in kinetic energy = Final kinetic energy (KEf) - Initial kinetic energy (KEi)
= 40,000 J - 25,000 J
= 15,000 J

Therefore, the increase in kinetic energy of the vehicle is 15,000 J.