A car having initial velocity 15ms‐¹ moves with a constant acceleration of 2ms‐² on a straight road. The displacement of car in 5th second of its motion is?
PLEASE DO WITH EXPLANATION
Answers
Answer:
Physics
Motion in a Straight Line
Uniformly Accelerated Motion
A particle has an initial v...
PHYSICS
A particle has an initial velocity of 9m/s due east and a constant acceleration of 2m/s
2
due west. The distance covered by the particle in the fifth second of its motion is:
December 26, 2019
avatar
Geeta Choudhary
Share
Save
ANSWER
Here the particle velocity will become zero in 4.5 seconds, as
v=u+at
0=9−2×t
t=4.5sec
Displacement in the same period will be
v
2
−u
2
=2as
−81=2s
s
4.5
=20.25m
Let us call the point of velocity being zero as Point A.
now body will start moving backwards,
displacement in next 0.5 sec from point A,
s=ut+
2
1
at
2
s
0.5
=
2
1
(−2)(0.25)
2
=−0.25m
hence distance covered is 0.25 m
(-ve sign indicates body moved in backward direction. It is to be noted that displacement and distance are not to be confused to be same)
Distance traveled in 4 seconds
s
4
=9×4+
2
1
(−2)(4)
2
s
4
=36−16=20
Thus,
distance covered in 5th second is
D=(s
4.5
+∣s
0.5
∣−s
4
)=20.5+0.25−20=0.5