The air in a hot-air balloon at 757 torr is heated from 17.0°c to 36.0°c. assuming that the moles of air and the pressure remain constant, what is the density of the air at each temperature? (the average molar mass of air is 29.0 g/mol.)

An Arrow (0.5 kg) travels with velocity 20 m/s to the right when it pierces an apple (2 kg) which is initially at rest. After the collision, the arrow and the apple are stuck together.

You see lightning before you hear thunder because A) light waves can travel through a vacuum. B) sound waves cannot travel through the air. C) light waves travel faster than sound waves. D) sound waves travel faster than light waves i think its c .

In the nature-nurture debate, nature refers to the influence of the environment.

Why do metals differ in specific heat? why is Al much higher than gold

Suppose you are at the earth's equator and observe a satellite passing directly overhead and moving from west to east in the sky. exactly 11.0 hours later, you again observe this satellite to be directly overhead. assume a circular orbit.

How does the wave model of electrons orbiting the nucleus account for discrete energy values?

An ecosystem is all the populations of organisms that live together and A. the microorganisms that depend on them. B. the organisms that generate energy from sunlight. C. the physical factors with which they interact. D.

Which statement about magnetic poles is accurate? A) Same magnetic poles attract, while different magnetic poles repel. B) Same magnetic poles attract, while different magnetic poles attract.

Power is measured in: A) J/s B) J2/s C) s/J D) s2/J

The amount or the strength of force is called its