Three identical blocks of masses $\mathrm{m}=2 \mathrm{~kg}$ are drawn by a force $\mathrm{F}=10.2…
Three identical blocks of masses $\mathrm{m}=2 \mathrm{~kg}$ are drawn by a force $\mathrm{F}=10.2 \mathrm{~N}$ with an acceleration of $0.6 \mathrm{~ms}^{-2}$ on a frictions surface, then what is the tension (in $\mathrm{N}$ ) in the string between the blocks $B$ and $C$?
9.2
7.8
4
9.8
Solution
Apply Newton's second law
$
\mathrm{F}-\mathrm{T}_{\mathrm{ab}}=m a ; \mathrm{T}_{\mathrm{ab}}-\mathrm{T}_{\mathrm{bc}}=\mathrm{ma} \quad \therefore \mathrm{T}_{\mathrm{bc}}=7.8 \mathrm{~N}
$
