Question

solve ....................​

Answer 1

Initial mechanical energy given to the bob, E = kinetic energy = ½ mv2

At the maximum height say ‘h’ the mechanical energy of the bob is only potential energy, so, PE = mgh

But due to loss of energy in air resistance, only 40% of initial mechanical energy is converted to PE.

So, PE = (40/100)KE

=> mgh = (0.4)(½ m)(52)

=> h = (0.4)(0.5)(25)(1/10) = 0.5 m