Why is a control important in an experiment?

An ant crawls along a sidewalk with a velocity of 0.1 m/s in a direction that is 45 degrees relative to the edge of the sidewalk. After 14sec, how far will it have traveled in the direction parallel to the edge of the sidewalk? A) 0.005m B) 0.

An air bubble underwater has the same pressure as that of the surrounding water. As the air bubble rises toward the surface (and its temperature remains constant), the volume of the air bubble. a) increase or decrease, depending on the rate it rises.

What is tan (61) ? А. 1.80 B. 0.49 C. 0.61 D. 0.87

How can you identify a moveable pulley? A. It has a fixed axle. B. It moves up and down with the load. C. It is anchored. D. It has been relocated from one location to another.

What kind of energy source transforms heat energy from the Earth into mechanical and electrical energy? a. Geothermal c. Solar b. Hydro-electric d. Turbine

How many layers of material were the roads made of? a. two c. four b. three d. five

Red light has a shorter wavelength than yellow light.

Approximately what is the parallax angle of a star that is 20 light-years away?

If the Earth and distant stars were stationary (motionless) in space, what would we observe about the wavelength from these stars? A. Wavelengths measured would match the actual wavelengths emitted. B.

Two fire trucks with sirens speeds towards and away from an observer. Which statement is true involving the Doppler effect observed by the observer?