The helium used to fill birthday balloons doesn’t come out of the air, but from out of the ground. Some of the gas might escape from the ground into the

atmosphere, but the majority of it is trapped in Earth’s crust. Based on what you have learned in today’s lab, give a reasonable explanation for the presence of helium gas in Earth’s crust.

Inductive or deductive? charles is hard to work with, since he always interrupts others. therefore, i do not want to work with charles in the development committee.

The long handle on a rake is a(n) a. lever b. screw c. wedge d. inclined plane

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?