Which is true of a mechanical wave? (Hurry up please, do quick) A. It can travel in a vacuum

B. It must have a medium.

C. It must travel in empty space.

D. Both sound and light are examples

The graph above shows how the price of cell phones varies with the demand quantity. the equilibrium price for cell phones is where both supply and demand quantities equal $100, 5,000 5,000, $100

Calculate the estimated density of each ball. use the formula d = m/v where d is the density, m is the mass, and v is the volume. record your calculations in table a of your student guide. given that the density of water is 1.0 g/cm3, make a prediction about whether each ball will float in water. record your prediction in table a. what is the estimated density of the table tennis ball? record your answer to the nearest hundredth

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j