Question

A BODY OF MASS 20 kg IS SUSPENDED VERTICALLY BY MEANS OF A STRING OF LENGTH 10 cm .WHAT WILL BE THE HORIZONTAL FORCE REQUIRED TO PULL THE MASS HORIZONTALLY THROUGH 6 cm ?

Answer 1

Answer:

120 N

Explanation:

The mass suspended from a string will be in a simple harmonc motion if it is pulled and and released.

If the mass of the pendulum is m and the length of the string is L then

the spring constant of a simple pendulum is given by

$k=\frac{mg}{L}$

Thus the spring constant

$k=\frac{20g}{10}$ N/cm

or, $k=\frac{200}{10}=20$ N/cm    (Taking g = 10 m/s²)

We know that in Simple Harmonic Motion, the restoring force is proportional to the displacement

Thus, F = -kx, where k is the spring constant and x is the displacement

Therefore the force required to pull the mass horizontally through 6 cm

$F=kx$   (negative sign is not considered as here the force is being imparted, so it is not against the direction of the displacement)

∴ $F=20\times 6$ N

or, $F=120$ N

Answer 2

Answer:

15 Kg-wt

Explanation:

hope it helps you