Physics

Problem

A uniform signboard of length

2.0\,\text{m}

and weight

40\,\text{N}

is hinged at its left end and kept horizontal by a light cable attached to the right end. The cable can be fixed at any angle

\theta

above the signboard. a. (a) Derive an expression for the tension

T

needed to keep the board in equilibrium in terms of

\theta

. b. (b) For what value of

\theta

is the required tension minimum? c. (c) Calculate this minimum tension and state whether it is within the safe limit of

100\,\text{N}

for the cable.