Question

The string in the figure is 50.0 cm long. When the 392 g ball is released from rest, it swings along the dotted arc. What is the kinetic energy of the ball at the bottom of the arc?

Answer 1

Change in kinetic energy=loss in potential eneregy of the ball:

Since ball is released from res initial kinetic energy is zero:

$\Rightarrow KE_f-KE_i=mgH$

$\Rightarrow KE_f=0.382*9.8*0.5$

$\Rightarrow KE_f=1.9208J$

Hence kinetic energy at the bottom of the arc=1.9208J