Question

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?

Answer 1

The distance travelled in first 8 s, x₁= 0 + 1 /2 (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, x₂ = (40 × 4) m =160 m 

Thus, the total distance x = x₁+x₂ = (160+ 160) m = 320 m