Question

Water is flowing through a horizontal pipe with speed 2m/s and power required to maintain the flow is 20 W.
If speed becomes double, then power required will be

Answer 1

answer : 40W

we know, Power = force applied × speed

given,

water is flowing through a horizontal pipe with speed 2m/s and power required to maintain the flow is 20W.

so, 20W = force applied × 2m/s

force applied = 10N........(1)

now question said, speed becomes double . e.g., speed = 4m/s

so, power = force applied × speed

from equation (1),

power = 10N × 4m/s = 40W

hence, power required will be 40W

Answer 2

Answer:P=F.v(force × velocity)

= ma .v=m{(v^2-u^2)/2s}v

=m{(v^2-0)/2s}v

=m(v^2)/2s×v=m/2s×v^3

So we can conclude that Pis directly proportional to cube of the velocity

P1/P2=(v1/v2)^3

20/P2=(2/16)^3

20/P2=(1/2)^3

20/P2=1/8

P2=160W

Explanation: