Question

A pendulum of length 2m left at A.When it reaches B,it looses 10 percent of its total due to air resistance.The velocity at B is:

Answer 1

The answer seems to be 6m/s.

This is a problem in physics that can be best solved using the principle of conservation of energy.

While solving this problem it is considered that the kinetic energy of the pendulum is equal to 0.9 times the potential energy of the pendulum.

For more details on how to solve such problems visit relevant resources available online.

Answer 2

The answer seems to be 6m/s.

This is a problem in physics that potential energy of the pendulum is converted into kinetic energyand is dissipated into the air.

Therefore, PE = KE = LOSS OF ENERGY………………………………….(1).

According to the problem, energy loss is 10 % of PE=0.10PE.

So, equation 1 becomes,

PE + KE+0.1 PE=0.9PE  =KE.

THEREFORE,

0.9 Mgh =0.5 V2. V2 = 1.8 gh. V= speed of the lowest point.

h= length of the pendulum= 2 m, g = 9.81 m/sec2.

putting the values of  g and h.

Velocity at B, V = 5.94 m/sec….Answer