Question

Reading shown in two spring balances S, and S, is 90 kg and 30 kg respectively when yhe lift is
accelerating upwards with acceleration 10 m/s. The mass is stationary with respect to to lift
calculate the mass of the block.​

Answer 1

Answer:

The mass is stationary with respect to the lift  calculate the mass of the block m=30

Explanation:

Let assume that the first spring balance is S1 and the second spring balance is  S2.

Given S1=90kg and S2=30kg.

The lift is  accelerating upwards with acceleration 10 m/s

Now as the free body diagram we have total of two equation.

Let the acceleration mass is ma and mass fopr the gravitational field is mg

S1= 90 - mg = ma....................(1)

and S2= mg - 30= ma.....................(2)

So, adding the two equation is we get

60g = 2ma

=> m=30 (∵g=a)