A 250-gram pendulum bob is initially constrained at a 53 degree angle by two strings. When the horizontal string is cut the pendulum begins to swing. As the pendulum bob passes through its equilibrium position, what will be its velocity?

Answer 1

Gravitational potential energy mgL(1-cos(θ) will be transformed into kinetic energy, (1/2)mv², where L=length of pendulum string,
θ=angle with vertical,
g=acceleration due to gravity
m=mass of pendulum (cancels out, so does not change answer)
Equate the two energies and solve for v.