The speed of a train increased from 20 mi/hr to 30 mi/hr in a distance of 500 ft. Calculate the average acceleration in ft/s2

Vo = 20mi/h * 5280Ft/mi * 1h/3600s. = 29.3 m/s.

V = 30/20 * 29.3 = 44 m/s.

a = (V-Vo)/t = (30-20)/t = 10/t.

d = 0.5*a*t^2 = 500 Ft.

0.5*(10/t)*t^2 = 500.
5t = 500.
t = 100 s.

a = 10/t = 10/100 = 0.10 Ft/s^2