The bob of a simple pendulum has a mass of 0.40 kg. The pendulum oscillates with a period of 2.0 s and an amplitude of 0.15 m.
At one point in its cycle it has a potential energy of 0.020 J.
What is the kinetic energy of the pendulum bob at this point?
A 0.024J
B 0.044 J
C 0.14 J
D 0.18 J

Protons have a positive charge and, collectively, give an element its atomic number.

Sound energy is produced when an object vibrates. examples are 1- a balloon popping2-a whistle3- a waterfall

stands for electromotive force and it is measured in volts. despite its name, it is not actually the force in the sense of being a "pushing" or "pulling" (not measured in newtons).an equation that relates emf,  ℰ,  to a battery's terminal voltage, v, current, i, and internal resistance, r, is    ℰ = v + irin this case, the emf can be interpreted as a voltage—a difference in electric potential.i would not say that it would be considered an energy. if emf can be defined as the energy/work per a unit charge from a battery or other electric source, then it is not strictly energy.