A pendulum has a mass of 1.5 kg and starts at a height of 0.4 m if it is released from rest how fast is it going when it reaches the lowest point of its path?

The speed of the pendulum when it reaches the lowest point of its path is 2.8 m/s

Explanation:

Given;

mass of pendulum, m = 1.5 kg

height of pendulum, h = 0.4 m

At the highest point, the velocity of the pendulum is zero and the kinetic energy  is zero, so the total energy at that point is potential energy;

U = mgh

At the lowest point, the height of the pendulum is zero and the potential energy is zero, so the total energy at that point is kinetic energy;

KE = ¹/₂mv²

Apply the principle of conservation of mechanical energy

KE = U

¹/₂mv² = mgh

¹/₂v²  = gh

v² = 2gh

v = √2gh

v = √(2 x 9.8 x 0.4)

v = 2.8 m/s

Therefore, the speed of the pendulum when it reaches the lowest path is 2.8 m/s