Question

A body of mass 0.01 kg starts to move in a viscous
liquid with initial velocity 5 m/s. If drag force is
10-3 N then find time after which velocity will
become 10 m/s
(1) 49 sec
(3) 149 sec
(2) 100 sec
(4) 200 sec
​

Answer 1

Answer: 100 sec

Explanation:

Answer 2

Answer:

Initial speed u=5 m/s

Final speed v=0.1 m/s

Force F=0.001 N

Acceleration a=

M

−F

​

=

0.01

−0.001

​

=−0.1 m/s

2

Using v=u+at

Or 0.1=5+(−0.1)t

⟹ t=49 s