The mass of a body in a lift at rest is m. If the lift ascends with uniform acceleration a, the effective mass will be

Options

A. `m(1+ (g)/(a))`
B. `m(1+ (a)/(g))`
C. `m(1-(a)/(g))`
D. `m (1-(g)/(a))`

Answer

B

Explanation

When lift ascends with uniform acceleration a, the apparent weight `W= m (g+a)`.
The mass in the lift appears to be `m_(1), m_(1)= W//g= (m(g+a))/(g)= m(1+ a//g)`