a bus is running at speed of 18 km/hr is stopped in 2.5 sec. by applying brakes.calculate the produced?

Hello....


v = 18 km/h = 18 x 1000/3600 = 5 m/s

ΔEc = 1/2 x m x v² - 0  (cause the bus stops) = mv²/2 = 25m/2  with m in kg

P = ΔEc/Δt with Δt = 2,5 s

To go further, we need the mass of the bus (m) or the length it took to stop the bus.

Supposing m = 10000 kg for instance

Then ΔEc = 25x10000/2 = 125000 J

And P = 125000/2,5 = 50000 W