Since sound travels faster in warm air, the speed of sound near the ground is increased, leading to a gradual reflection of sound waves.

True or False?

The ecliptic is the annual path of the Sun relative to the background stars. the shortest day of the year, when the Sun takes its lowest path in the sky. the location of the North Star on the celestial sphere.

Suppose you have a scientific question you are interested in answering. What would you normally do before you make your hypothesis?

Express each of the following as indicated: a) 2 dm expressed in millimeters b) 2 h 10m expressed in seconds c) 16 g expressed in micrograms e) 0.675 mg expressed in grams f) 462 um expressed in centimeters g) 35/h expressed in meter per second

What is the basic definition of a black hole? a. any compact mass that emits no light b. a dead star that has faded from view any object from which the escape velocity exceeds c. the speed of light any object made from dark matter d.

A penny dropped into a wishing well reaches the bottom in 1.5 seconds. what was the velocity at impact?

How do the tension of the cord and the force of gravity affect a pendulum? A. They are the competing forces that act on a pendulum as it swings. B. They are the two factors that affect the period of a pendulum. C.

What is an example of static friction

What is the configuration of NE

Why does ice generally have very little friction when it is in contact with other materials?

A stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. What is the speed of the car?