Question

A car started a race from START line and from rest, and accelerated with the acceleration of 3 m/s2 for 8 seconds. Then the decelerated with the acceleration of -1.6 m/s2 and went with that acceleration for 15 seconds. What was the car’s position from the START line after 8+15 seconds from the start of the race? Choose the answer closest to yours.

Answer 1

s
1
​
=ut+(1/2)at
2

=0+
2
1
​
×5×8
2

=160 m.
The velocity attained in 8 seconds is given by
v=u+at
=0+5×8=40 m/s.
The distance traveled in the next 4 seconds is
s
2
​
=40×4=160 m.
So, the total distance traveled by the car is s
1
​
+s
2
​
=160+160=320 m