Q15Short answer
A car starts from rest and moves along the x-axis with constant acceleration 5 m s–2 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?
Show answer
The distance travelled in first 8 s, x1= 0 + (5) (8)2 = 160 m. At this point the velocity v = u+ at = 0 + (5×8) =40 m s–1 Therefore, the distance covered in last four seconds, x 2 = (40 × 4) m =160 m Thus, the total distance x = x 1+x 2 = (160+ 160) m = 320 m x x