Q.9) 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?
Answers
Answer:
Given: A car starts from rest and moves along the x-axis with a constant acceleration of 5 m/s2 for 8 seconds
To find: what distance will the car cover in 12 seconds since it started from rest
Solution:
We know that,
But given that, the initial velocity is zero. Therefore, the distance covered by the car in first 8 seconds is
=>
=>
Therefore, the velocity attained at the end of 8 seconds is:
from,
=>
Therefore, since the car has moved with constant velocity from 8th second to 12 second, the distance traveled is
Therefore, the total distance traveled is
Answer:
s =ut+(1/2)at^2
=0+ 21 ×5×82
=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 iss2
=40×4=160 m.
So, the total distance traveled by the car is s
1 +s 2
=160+160=320 m