Question

A car starts from rest and accelerates with 2 m/s2
for 10 seconds, after maintaining the
velocity for 10 seconds, it comes to rest decelerating 1m/s2

i) Draw the shape of V-t graph. II) Find the maximum velocity attained and the total
distance travelled during the journey.

Answer 1

Explanation:

metres/second

Total distance travelled is 500 metres

Initial speed (U) = 0

Acceleration (A) = 2

Time (T) = 10

Final speed (V) = U + AT

= 0 + 10 x 2

= 20

Hence maximum velocity attained is 20 m/s

Deceleration (D) = -1

Initial velocity after 20 seconds = V = 20

Final velocity (V1) = 0

Time (T1) = (V1 - U) / D

= (0 - 20) / (-1)

= 20 seconds

Total distance travelled = Distance while accelerating + Distance while decelerating + Distance without acceleration

= (0.5 x 2 x 10^2) + (20^2 / 2 x 1) + (20 x 10)

= 100 + 200 + 200

= 500 metres