1. You are asked to build some models of methane molecules for a science fair. You will arrange your
model atoms as shown on
the right, but you will
use ping-pong balls and tennis balls to model
hydrogen atoms and carbon atoms. If
you
have 12
ping-pong balls, how many tennis balls will you
need? Use the model you just developed to justify
your answer.

Science

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.

Which of these statements best explains how the hydrosphere interacts with the atmosphere to affect global climate? mountains block rain clouds and cause changes in global rainfall and evaporation. humans burn fossil fuels to produce greenhouse gases which cause global warming. humans cut down trees which affects the amount of oxygen in different parts of the globe. greenhouse gases, like carbon dioxide, dissolve in oceans and prevent global warming.

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.