When you drop a penny off the roof of a building, it takes 10 seconds to reach the ground. How high is the roof?

Nuclear energy is the energy stored in the blank of an atom.

On a cold winter day when the temperature is - 20∘C, what amount of heat is needed to warm to body temperature (37 ∘C) the 0.50 L of air exchanged with each breath? Assume that the specific heat of air is 1020 J/kg⋅K and that 1.0 L of air has mass 1.

A substance has a mass of 360g and a volume of 7.5 cm^3. What is its density

An electron with a charge of - 1.6 * 10^-19 coulombs experiences a field of 1.4 * 10^5 newtons/coulomb. What is the magnitude of the electric force on this electron due to this field? A. 1.6 * 10^-3 newtons B. 1.4 * 10^24 newtons C. 2.

During a baseball game, a baseball is struck at ground level by a batter. The ball leaves the baseball bat with an initial velocity v0 = 26 m/s at an angle θ = 17° above horizontal.

A glass window is a clear object that light passes through as it travels in a straight line. This is a good example of A. refraction of light. B. transmission of light. C. absorption of light. D. reflection of light.

Why is net force a vector sum A. All forces have direction and magnitude B. Forces can only be attractive C. All forces are contact forces D. There are four fundamental forces

Does the elf owl's small size allow it to live in cacti

If grapefruit juice has a ph of 3.0 and egg white have a ph of 8.0, which contains more h + ions? how many more?

Consider a single photon with a wavelength of λ, a frequency of ν, and an energy of e. What is the wavelength,? Consider a single photon with a wavelength of λ, a frequency of ν, and an energy of e.