Question

7gr
A pendulum bob is given velocity u = at
V 2
lowest point where r is length of the string then the
minimum velocity of bob in subsequent motion is
gr
V=
then value of P is.
P​

Answer 1

Answer:

Using conservation of energy in vertical motion of pendulum when it reaches horizontal position,

2

1

mv

h

2

+mgL=

2

1

mv

b

2

Velocity at the bottom is given by,v

b

=

5gL

v

h

=

3gL

------ (1)

Tension at the horizontal position is =T=

L

mv

h

2

----- (2)

=3mg ; (Substituting v

h

from eqn 1 in eqn2)

∴ Net force on the bob is =

(3mg)

2

+(mg)

2

=

10

mg