A man weighs 80 kg. He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of 5 ms^-2. What would be the reading on the scale ? (g = 10 ms^-2)

Mass of man M = 80Kg
Acceleration of lift, $a=5m{s}^{-2}$  
When lift is moving upwards the reading of weighing scale will be equal to R. The equation of motion gives

$\begin{array}{l}R-Mg=Ma\text{\hspace{0.17em}\hspace{0.17em}or\hspace{0.17em}\hspace{0.17em}}R=Mg+Ma=M\left(g+a\right)\\ \therefore R=80\left(10+5\right)=80\times 15=1200\text{N}\end{array}$