The speed of a bycyle reduce from 20 m/s to 4 m/s after travelling 80m .calculate
a= -16 m/s / t = acceleration
but what is t?
average speed during stop = 24/2 = 12 m/s
so time = 80/12 = 20/3 seconds to stop
so
a = -16(3/20) =-12/5 = -2.4 m/s^2