Question

Q4. Write the expression for velocity and tension in string at highest and lowest point when a

body just completes one vertical circle.
​

Answer 1

Answer:

vertical circular motion (ref. image)

use energy conservation at pt A & C

Assume A as ground level

2

1

mn

2

=2mgR+

2

1

mv

′2

v

2

=4gR+v

′2

T−mgcosθ=

R

mv

2

at ptAθ=0

o

At pt.Cθ=π(180

o

)

T

A

−mg=

R

mV

2

...(1)

T

C

+mg=

R

mV

′2

....(2)

subtract (2) from (1)

T

A

−T

C

−2mg=

R

m

(V

2

−V

′2

)

T

A

−T

C

=2mg+

R

m

(V

2

−V

′2

)

V

2

−V

′2

=4gR

∴T

A

−T

C

=2mg+

R

m

⋅4gR

=6mg

hope it's helpful