Question

Two forces $F_1$ and $F_2$ act on a thin uniform elastic rod placed in space. Force $F_1$ acts at right end of the rod and $F_2$ acts exactly at centre of the rod as shown (both forces act parallel to length of the rod).

$\left(i\right)$ $F_1$ causes extension of rod while $F_2$ causes compression of rod.
$\left(ii\right)$ $F_1$ causes extension of rod $F_2$ also causes extension of rod.
$\left(iii\right)$ $F_1$ causes extension of rod while $F_2$ does not change length of rod.

The correct order of $True/False$ for above statements is

• A. $TFF$
• B. $FTF$
• C. $FFT$
• D. $FFF$

Answer 1

The correct option is C $FFT$


The force $F_1$ causes extension in rod.

$F_2$ causes compression in left half of rod and an equal extension in right half of rod. Hence $F_2$ does not effectively change length of the rod.

So, only $\left(iii\right)$ is true.