Answer:
a=6.65 m/s²
F(top)=9.96 N
Explanation:
Given that
m= 300 g= 0.3 kg
F= 15 N
Lets acceleration of the chain is a
So from Newton's law
F(net) = m(total) a
F(net) - 3 m g= 3 m a
Here F(net) = F
Take g=9.81 m/s²
So now by putting the values
F - 3 m g= 3 m a
15 - 3 x 0.3 x 9.81 = 3 x 0.3 x a
a=6.85 m/s²
F(top) - 2 m g= 2 m a
F(top)= 2 ma + 2 mg
F(top)=2 x 0.3 (9.81 +6.85 )
F(top)=9.96 N