Hink about the friction activity. Return to this activity to see it again if you need to. Explain what happened in each of the two demonstrations, and then compare them. Use the terms resistance, vacuum, gravity, velocity, and friction.

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but hastwice as much mass, its momentum isa. zero. b. doubled. c. quadrupled. d. unchanged.

An unknown solution has a pH of 8. How would you classify this solution? A) The substance is an acid. B) The substance is a base. C) There is not enough information to answer the question.

What organisms apart from algae would have needed to be present to remove carbon dioxide from the early atmosphere?

Every time you stir a pitcher of lemonade to make the sugar dissolve faster, you are observing which of the following?

Which of the following types of pollution is NOT linked to coal-burning power plant emissions? A) acid rain B) global warming C) ozone hole D) smog

A substance has a specific heat of 0.870 J/g°C. It requires 2,000.0 joules to increase the temperature of 10.0 grams of the substance from its original temperature to its final temperature. By how many degrees did the substance increase? A 87.

How many earth years does it take mars to orbit the sun

Which represents a system that is almost completely closed?

If many household substances classify as acids or bases what is the ph scale

A protostar forms once the nebular cloud condenses and the core begins