Astationary police officer directs radio waves emitted by a radar gun at a vehicle moving toward the officer. compared to the emitted radio waves, the radio waves reflected from the vehicle and received by the radar gun have a
(1)longer wavelength
(2)higher speed
(3)longer period
(4)higher frequency

What produces light and all other electromagnetic waves? a) the photoelectric phenomena b) heated metals c) charged particles d) radioactive samples (pls explain if you can : )

What type of nuclear decay causes the atomic number of an element to increase by 1?

Aperson stands on a platform, initially at rest, that can rotate freely without friction. the moment of inertia of the person plus the platform is ip. the person holds a spinning bicycle wheel with its axis horizontal. the wheel has moment of inertia iw and angular velocity ωw. take the ωw direction counterclockwise when viewed from above. part a what will be the angular velocity ωp of the platform if the person moves the axis of the wheel so that it points vertically upward?