A man of mass 70 kg stands on a weighing scale in a lif which is moving
downwards with a uniform acceleration of `5ms^(-1)`,

Explanation

Here , m = 70 kg , g = `10m//s^(2)`
The weighing machine in each case measures the reaction R i.e ., the apparent weight .
When the lift moves downwards with `a=5ms^(-2)`
R = m (g-a) = 70 (10-5) = 350 N`