Question

A car accelerate uniformly from 36 km per hour to 72 km per hour in 10 seconds calculate:1- acceleration 2- distance covered by the car in that time.

Answer 1

Initial speed u = 36 km/h = 36 x 1000/3600 m/s = 10 m/s
Final speed v = 54 km/h = 54 x 1000/3600 m/s = 15 m/s
Time t = 10 s
Acceleration a = (v - u)/t = (15 - 10)/10 = 5/10 = 0.5 m/s2.

Distance travelled  S = ut + ½ at2
                                     = 10 x 10 + ½ x 0.5 x 10 x 10     m
                                     = 100 + 25 = 125 m

Answer 2

v=u+at
72= 36+ 10a
72-36=10a
36/10=a
3.6=a
s= ut +1/2att
360+1/2*36
360+12
372km distance