What are the types of energy sources based on the time of replacement ?

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Give an example in which the electrical energy changes to light energy

Object a has a length of 3 cm, a width of 2 cm, and a height of 4 cm. object b is dropped into a graduated cylinder. it displaces 19 ml of water. the volume of object a is: a: greater than the volume of object b b: less than the volume of object b c: equal to the volume of object b