Aduck floating on a lake oscillates up and down
5.0 times during a 10.-second interval as a
periodic wave passes by. what is the frequency
of the duck’s oscillations?
(1) 0.10 hz (3) 2.0 hz
(2) 0.50 hz (4) 50. hz
what formula do i use for this? (in accordance with the nys physics reference table)
the answer is 2

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

In a system, when potential energy decreases, then entropy also decreases. true false

While standing outdoors one evening, you are exposed to the following four types of electromagnetic radiation: yellow light from a sodium street lamp, radio waves from an am radio station, radio waves from an fm radio station, and microwaves from an antenna of a communications system. rank these type of waves in terms of increasing photon energy.