The electric field just above the surface of the earth has been measured to be 139 N/C downward. What total charge (sign and magnitude) on the Earth is implied by this measurement

What type of light does this light bulb produce most (i.e. at what wavelength does the spectrum have maximum intensity)?

Adolphin emits ultrasound at 100khz and uses the timing of reflections to determine the position of objects in the water. part a what is the wavelength of this ultrasound? assume that temperature of water is 20 degrees c. answer in cm

What describes the particles in a liquid