The length of a ballistic pendulum is `1 m` and mass of its block is `1.9 kg`. A bullet of mass `0.1 kg` strikes the block in horizontal direction with a velocity `100 ms^(-1)` and got embedded in the block. After collision the combined mass swings away from lowest point. The tension in the strings when it makes an angle `60^@` with vertical is `(g=10 ms^(-2))`.

Options

A. 20 N
B. 30 N
C. 40 N
D. 50 N

Answer

C

Explanation

`m u=(m+M) v`, If `v_(theta)` is Velocity at an angle `theta`.
`v^(2)-v_(dot)^(2) = 2gl(1-cos^(●))`, find `v_(theta)`
then `T_(theta) = (mv_(theta)^(2))/(r) +mg cos theta`.