What can you observe to know that when clear methane gas is burned it is a chemical change?

1) Change of color

2) Formation of a precipitate

3) Change in mass

4) Formation of a gas

5) Change in temperature

6) Change in shape

A gas powered model airplane has a mass of 2.50 kilograms. A student exerts a force on a cord to keep the airplane flying around her at a constant speed of 18.0 meters per seond in a horizontal, circular path with a radius of 25.0 meters.

A large container is pulled 20 meters with 40 newtons of force. The power exerted is 64 watts. How long did it take to move the container? A. 12.5 s B. 40 s C. 125 s D. 250 s

A sailboat accelerates at a rate of 2 m/s? and has a mass of 800 kg. What is the net force acting on the sailboat? Answer

Under the Doppler effect, an observer behind a moving wave source observes A) increased wave frequency B) no wave frequency C) decreased wave frequency D) unchanging wave frequency

Which of the following statements about current theories on global warming is true? a. Scientists generally agree that global warming is taking place. b. Some scientists think that we should accelerate global warming. c.

Describe one example of competiton of tropical dry forest

What is the center of a tornado called A. the eye B. The center C. The middle road D. The vortex

Is it legal in Florida for a math teacher forces the kids to do push ups?

Acceleration is best defined as the rate of change of blank of an object

Zirconium has an atomic number of 40. How many neutrons are there in an isotope of zirconium-92?