Question

$80$ railway wagons all of same mass $5\times 10^3$ $kg$ are pulled by an engine with a force of $4\times 10^5$ $N$ . The tension in the coupling between $30^{th}$ and $31^{st}$ wagon from the engine is

• A. $25\times 10^4$ $N$
• B. $40$ $\times 10^4$ $N$
• C. $20$ $\times 10^4$ $N$
• D. $32$ $\times 10^4$ $N$

Answer 1

Answer: (A)

Railway waygons to be pulled = 80 - 30 = 50
$\therefore m=50\times 5\times 10^{3}kg$
$a=\frac{\text{F}}{\text{80 }\text{M}}=\frac{4\times {\text{10}}^5}{\text{80}\times 5\times {\text{10}}^3}$
$\Rightarrow {\text{F}}_{\text{30}}=\text{50}\times 5\times {\text{10}}^3\times \frac{4\times {\text{10}}^5}{\text{80}\times 5\times {\text{10}}^3}$ $=25\times 10^{4}N$