Question

A bob is suspended from an ideal string of length 'l'. Now it is pulled to a side till the string makes an angle 60° to the vertical and whirled along a horizontal circle. Then the period of revolution is
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Answer 1

The period of revolution is π √(2L / g). This can be calculated in the following ways:

• We know that time period can be represented as = 2π √(L cos Θ / g) , where L represents the length of the string and Θ is the angle that the string makes with the horizontal.

• Here, Θ = 60°

• Thus, T = 2π √(L cos 60 / g)

                     = 2π √(L / 2g)

                     = √(2L / g)

Answer 2

Answer:

π√2l/g

Explanation:

T= 2π √lcos theta/g

=> 2π √ l cos 60 /g. (:. cos 60 = 1/2)

=> 2π √l/2g

=> π √2l/g