I need to add an important bit of info, that so far hasn't been mentioned.
Everyone has been commenting on the energy a capacitor of a certain voltage and capacitance can store/release
You need to understand that the voltage rating printed on the side of a capacitor has a totally different purpose
This voltage rating is the maximum voltage that the capacitor can sustain BEFORE electrical breakdown of the dielectric
material between the plates occurs.
so consider that a 50V cap ( depending on the circuit it's in) may not have 50V across it, there may only be 10V
The dielectric is an insulator between the capacitor plates. It may be made up of many different types of materials
eg ... wet paper, dry paper, mylar, ceramic, air, vacuum to name a few. each of these dielectrics have different properties
that determine the use of the capacitor in a particular place in a circuit
variable capacitor with air dielectric
View attachment 23063
electrolytic capacitor ( wet paper dielectric)
View attachment 23062
Ceramic dielectric cap
View attachment 23061
cheers
Dave