question_answer

A mass of 10 kg is suspended from a spring balance. It is pulled aside by a horizontal string so that it makes an angle of \[{{60}^{o}}\] with the vertical The new reading of the balance is

A)  20 kg - wt           

B)  10 kg - wt

C)  \[10\sqrt{3}\,kgwt\]     

D)  \[20\sqrt{3}\,kg-wt\]

Correct Answer: A

Solution :

The situation is shown in figure At an angle of \[{{60}^{o}}\],                 \[T\,\cos \theta =mg\]                 \[T=\frac{mg}{\cos \theta }=\frac{10\,g}{\cos \,{{60}^{o}}}\]                 \[=\frac{10}{1/2}kg-wt\].                 = 20 kg-wt