The doppler effect is the change in observed frequency due to

a. the type of medium the wave is in

b. the type of wave

c. the original frequency of the source

d. the motion of the source or observer

What do sound waves and infrared waves have in common, what makes them different

The following diagram shows the path of a planet around the sun. Kepler discovered that

1. A carbon atom contains 6 protons and 6 electrons. In order for the carbon atom to become negatively charged, what must happen?

A 0.065-kg tennis ball moving to the right with a speed of 15 m/s is struck by a tennis racket, causing it to move to the left with a speed of 15 m/s. if the ball remains in contact with the racquet for 0.

The acceleration due to the earth's gravity, in si units, is 9.8 m/s2. in the absence of air friction, a ball is dropped from rest. its speed on striking the ground is exactly 60 m/s. for what time interval was the ball falling?

Shivering to warm up illustrates which characteristic of life? A. adaptation to environment B. homeostasis C. getting energy D. growth

Dante pours hot tea into a mug that is cool to the touch. Which best explains what will happen now?

What type of resource can be regenerated or replenished by biochemicl cycles

How much work is done lifting a 12-m chain that is initially coiled on the ground and has a density 2 kg/m so that its top end is 11 m above the ground? (Assume that acceleration due to gravity is g = 9.8 m/s2.)

Which is a correct step in a scientific experiment involving acids and bases?