Question

A mass of Mkg is suspended by a weightless string. The horizontal force that is required to displace it until the string making an angle of 45º with the initial vertical direction is

(a) Mg ( √2 - 1)

(b) Mg ( √2 + 1)

(c) Mg√ 2

(d) Mg/√2.

.

Answer 1

(a) : Work done in displacement is equal to gain in potential energy of mass