if it takes a tennis ball falls straight down for 4 seconds from the top of a roof, how high above the ground is the roof?

Which system consists of nerves that initiate communication?

Which type of wave is more dangerous for humans? Microwaves or x-rays?

Why water is matter? what is the reason

A 7.00-kg bowling ball moves at 3.00 m/s. How fast must a 2.45-g Ping-Pong ball move so that the two balls have the same kinetic energy?

How do we use velocity curves (obtained from spectroscopy to show that some extrasolar planets are close to their host stars?

Which statement about ammeters and voltmeters is true? A. Current and voltage are the same throughout a circuit so where you place the ammeter and voltmeter doesn't matter. B.

Teens realize that things may be "shades of gray" after they enter Piaget's social stage. identity crisis stage. menarche stage. formal operational stage.

Technician A says that fractured rods have a unique mating surface and that only the cap that was fractured is the one that will fit that rod. Technician B says that a powdered metal rod is less expensive, lighter, and as strong as a forged rod.

What is the expected wavelength (in cm) of 10.5 ghz microwaves in free space?

There are 5,280 feet in 1 mile and 12 inches in one foot. How many inches are in a mile?