Answer:
0.80 m
Step-by-step explanation:
Neglecting friction, the total mechanical energy of the pendulum is constant.
E = K + U where K = kinetic energy and U = potential energy.
At its release point of 0.80 m, the pendulum bob has a mechanical energy which is equal to its potential energy, since, its initial kinetic energy is zero. By the time the bob swings to the other end, it has a mechanical energy equal to it initial potential energy since total energy is conserved.
Neglecting friction, the pendulum bob would swing back to its original height of 0.80 m since the total mechanical energy is conserved and at its highest point, it is purely potential energy.
So, the height the pendulum bob swings to after release from a height of 0.80 m neglecting fiction is 0.80 m.