Question

A 10 m long iron chain of linear mass density 0.8 kg m–1 is
hanging freely from a rigid support. If g = 10 ms⁻², then the
power required to left the chain upto the point of support in
10 second
(a) 10 W (b) 20W
(c) 30 W (d) 40 W

Answer 1

Answer:

(b) 20W

Explanation:

here is your answer.

hope it will help you

Answer 2

Question:-

A 10 m long iron chain of linear mass density 0.8 kg m–1 is

hanging freely from a rigid support. If g = 10 ms⁻², then the

power required to left the chain upto the point of support in

10 second

(a) 10 W (b) 20W

(c) 30 W (d) 40 W

${\red{\underline{\underline{\bold{Answer:-}}}}}$

⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐

first of all find centre of gravity of chain.

here centre of gravity lies at the centre of length of chain . e.g., C.O.G = h = 10m/2 = 5m

given, mass density = 0.4 kg/m

length of chain , l = 20m

so, mass of chain = l × mass density

= 20 × 0.4 = 8 kg

so, potential energy of chain = mgh

= 8 × 10 × 5 = 400J

power = energy/time,

so, power = 400/2 = 200W

hence, power required to lift the chain upto the point of support in 2 s is 200W

⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐⭐

hope it helps you..