The person o( mass 50 kg slands on a weighing scale on a lift. If the lift is ascending upwards with a uniform acceleration of `9ms^(-2)`, what would be the reading of the weighting scale? `("Take g"=10ms^(-2))`

Options

A. 50kg
B. 60kg
C. 96kg
D. 176kg

Answer

C

Explanation

The reading on the scale is a measure of the force on the floor by the person. By the Newton's third law this is equal and opposite to the normal force N on the person by the floor.
When the lift is ascending upwards with the acceleration of `12ms^(-2)`, then `N=80 xx10=80xx12`
`or N=80 xx10+80xx12=80(10+12)=960 N`
THe reading of weighing machine is 95 kg.