At 2:00 pm a car’s speedometer reads 30 mi/h. At 2:10 pm it reads 50 mi/h. Show that at some time between 2:00 and 2:10 the acceleration is exactly 120 mi/h2
avg acceleration = (50-30)/(10/60) = 120mi/h^2
so, at some point in time between 2:00 and2:10, the acceleration must have been 120 mi/h2
this is because acceleration is a continuous function and Avg value over an interval must be the instantaneous value at some point in time.