A dynamometer D is attached to weights of mass M = 10 kg and m = 10 g. Force F=20 N and 10 N are applied to the weights. What will happen to the weights and what will the dynamometer show if:
The force f is applied to larger weight and F to smaller weight.

Explanation

In all the cases as net pulling force is F -f, while the mass involved is m+ M.
Acceleration (a) `("force")/("mass")=(F-f)/(m+M)=1(m)/(s^2).......(i)`
So, the whole system will inove in the direction of larger force with acceleration given by Eqn. (i)
For this case, equations of motion form and M will be respectively,
`F-T_2=ma` and `T_2-f=Ma`
Either of these equations in the light of Eqn. (i), yields
`T_2=(MF+mf)/(m+M)=F=20N........(iii)`