Question

A particle B of mass 5 kg is attached to a frictionless pivot A by a thread of length
d – 0.2 m so that B hangs freely. At some instant of time a strong wind begins to
apply a constant horizontal force F = 100 N to B, as a result it rotates about A in
a vertical plane. Find the speed (in m/s)
of B at the instant when the string is horizontal
​

Answer 1

Explanation:

• So the initial velocity u = 0, F = 100 N
• By work energy theorem we have  
• Net work done on a body W net = Net change in kinetic energy Δ K.E
•              W net = Δ K.E
•          W f + W mg = Δ K.E          (Now S = √2 d)
• So F x S cos theta + mgh (-1) = ½ mv^2 – 0
•      100 x √2 d x 1 / √2 – 5 x 10 x 0.2 = 5/2 v^2
•            5/2 v^2 = 20 – 10  
•                v^2 = 10 x 2 / 5
•               v^2 = 4
•              Or v = √4
•              Or v = 2 m / s

Reference link will be

https://brainly.in/question/3630504

https://brainly.in/question/11206079