A car starts from rest and moves along the x-axis with a constant acceleration of 5 m/s2 for 8 seconds. If it then continues with constant velocity, what distance will the car cover in 12 seconds since it started from the rest?

Soln:

Car Starts from rest hence Initial velocity u=o acceleration a=5 m/s2 and time t=8s v = u+at

v = 0+5×8

v = 40ms-1

From second equation s = ut +

12

at2

s = 0x8 +

12 x5x(8)2

s =

12 x5x(8)2

s =

12

x5x64

s = 5×32 =160 is the distance covered in 8 seconds.

Therefore, the total distance covered in 12 seconds is 160+160=320m