Evaluate ` sec 65° + cosec 75°.`
`a) Cosec 25° + Sec 15°`
` b) Cosec 25° – Sec 15°`
` c) Cosec 15° + Sec 25°`
` d) Cosec 15° – Sec 25° `

Answer

A, B, C, D

Explanation

Let the mass of both the particle and the spherical body m the particle velocity v has two components `v cosalpha` normal to the sphere and `v sin alpha` tangential to the sphere.
After the collision, they will exchanged their velocity . So, the spherical body wil have a velocity `vcosalpha` and the particle wl not have any component of velocity in this direction.
[The collision will be due to the component `v cos alpha` in the normal direction
but, the tantential velocity, of the particke `vsiN/Alpha` will be uN/Affected]
So, velocity of the sphere `=v cos alpha`
`=v/r sqrt(r^2-p^2)`
and velocity of the particle `=vsiN/Alpha`
`(vp)/r`.