What must quantities have before they can be added or subtracted?

What are the two roles of bacteria in the nitrogen cycle?

Which type of friction prevents an object from moving? A. kinetic friction B. static friction C. rolling friction D. fluid friction

When talking about variables in a scientific experiment, describe how you know what the independent variable, dependent variable, control and constant are in the experiment. How do you know which one is which?

During a collision with a wall, the velocity of a 0.200-kg ball changes from 20.0 m/s toward the wall to 12.0 m/s away from the wall. If the time the ball was in contact with the wall was 60.

A white dwarf is a large star capable of fusing elements.

There is an explosion on the surface of a lake and two people John and Nil hear its sound. John is 150m away on a boat and Nil is 150m below the surface of water. Who would hear the sound first and why?

It takes 3.3 j of work to stretch a hooke's-law spring 15 cm from its unstressed length. how much the extra work is required to stretch it an additional 11.3 cm? answer in units of j.

Reading Africa's Big Break 1. Which of the following best describes the purpose of the article? a. The passage is an advertisement to encourage you to buy something. b. The passage is to persuade you to make a certain decision. c.

What must quantities have before they can be added or subtracted?

A brick sits on the top of a hill with a gravitational potential energy of 245 J. To determine the gravitational potential of the brick, we would also need to know which one of the following