Question

A U-shaped smooth wire lying in horizontal plane,

has a semicircular bending between A and B as

shown in figure. A bead of mass m moving with

uniform speed v through the wire enters the semi

circular bend at A and leave at B. The average force

exerted by bead on the part AB of wire is​

Answer 1

Answer:

AsthebeadtravelsfromAtoB,

Changeofmomentum=2mv

Timeoftravel=

v

s

=

v

(

2

πd

)

=

2v

πd

∴Averageforce=

timeoftravel

changeinmomentum

=

(

2v

πd

)

2mv

=

πd

4mv

2

Hence

option (B) is correct answer.

Answer 2

Answer:

post the image for proper visual