A man of mass `m` slides down along a rop which is connected to the celling of an elevator with deceleration `a` relative to the rop.If the elevator is going upward with an acceleration relative to the ground, then tension in the rop is

Options

A. `mg`
B. `m (g + 2a)`
C. `m (g + a)`
D. zero

Answer

B

Explanation

`a_(mr) =` acceleration of man relative to rop
`= a_(m) - a_(r)`
`a_(m) = a_(mr) + a_(r)`
`= (a) + (a)`
`= 2a`
`T - mg = m (a_(m))`
`= m (2a)`
:. `T = m (g + 2a)`