This pendulum is at

minimum displacement
maximum displacement
equilibrium

Abucket full of water weights 4 kg and water well is 10m deep. a girl draws water from the well. it takes the girl 3 minutes to draw a bucket full of water from the well. what is the power of the girl?

Ihave a density of 1.61g/cm^3 and a mass of 28g. find the missing value

In a classical model of the hydrogen atom, the electron moves around the proton in a circular orbit of radius 0.053 nm. what is the electron's orbital frequency? what is the effective current of the electron?