Question

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

Answer 1

for distance moved in first 8 second
s=ut +(1/2) at^2
s=(1/2) 5×64
s=5×32
s=160m
final velocity at the end of 8 second
v=u+at
v=at
v=5×8
v=40m/s
since after 8 sec the car moves with uniform velocity
therefore, the distance travelled by car in next four seconds will be
s=vt
s=40×4
s=160m
therefore the total distance travelled by car is 160+160=320m