What does it mean when an electromagnetic wave has low energy?

A. it has a long wavelength

B. It has a short wavelength

C. it has a short amplitude

D. It has a high frequency

Find the magnetic field a distance r from the center of a long wire that has radius a and carries a uniform current per unit area j in the positive z direction.

Aplayground slide is 8.80 ft long and makes an angle of 25.0° with the horizontal. a 63.0-kg child, initially at the top, slides all the way down to the bottom of the slide. (a) choosing the bottom of the slide as the reference configuration, what is the system's potential energy when the child is at the top and at the bottom of the slide? what is the change in potential energy as the child slides from the top to the bottom of the slide? (include the sign of the value in your answer.)

How does the strength of the electrostatic force between an electron and a proton compare to the strength of the gravitational force between them?