A building contractor needs 500 sheets of drywall. Which is the most cost-effective way to buy them? 50 sheets at a time for $600 100 sheets at a time for $800 250 sheets at a time for $2,500 500 sheets at a time for $4,500

Afisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surface of the water. it takes a time of 2.20 s for the boat to travel from its highest point to its lowest, a total distance of 0.670 m . the fisherman sees that the wave crests are spaced a horizontal distance of 5.80 m apart. (a) how much is the wavelength? (b) find the period of the wave. (c) how fast are the waves traveling? (d) what is the amplitude a of each wave?