How do you know if a wave is a transverse wave or a longitudinal wave?

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

Hydrogen and helium are both members of?

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)