Question

If velocity v of a particle moving on a straight line
as a function of time t is given as v = 5-t (m/s)
then the distance covered by the particle in first
10 s is
(1) 5 m
(2) 15 m
(3) 25 m
(4) 50 m​

Answer 1

Explanation:

v = 5-t

s = vdt = 5t- t^2/2 ( after integration)

as distance is asked we cannot directly put 10 in equation as it will not give distance but it will give displacement.

at t=5, v=0 means particle direction is reversed.

so displacement in 0 to 5 sec d1 = 25- 12.5 = 12.5

displacement in 5 to 10 sec d2= 0 - 12.5

= - 12.5

distance = |d1| + |d2| = 25 m