Astudent visits the beach during a very hot day. she steps on the sand and jumps because it is so hot. what type of heat transfer is demonstrated by the sand in this example?
a. conduction
b. radiation
c. convection
d. transmission

Keneila is attempting to ski down a 20 m high friction free hill for the first time. she has a speed 10 m/s at the top. what is her kinetic energy when she is a the bottom, 20 m ? (a)2500 j (b)9800 j (c)12300 j (d)3100j (e)15000j

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

Aphoton is absorbed by an electron that is in the n = 3 state of a hydrogen atom, causing the hydrogen atom to become ionized. very far away from the nucleus, the released electron has a velocity of 750,000 m/s. what was the wavelength of the absorbed photon?