Question

A cabbie is trying to stop when he notices a fare is whistling them over. The car has 18750 J of energy. If the cab is 2100 kg. How fast was it moving?

Answer 1

Step-by-step explanation:

ASSUMING that the cab has ONLY kinetic energy,

(it's not sitting over a loaded spring, high on a hill, on fire)

KE = ½mv²

v = √(2KE/m)

v = √(2(18750)/2100) = √17.85714...

v = 4.225771...

v = 4.23 m/s or about 15.2 km/hr