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

Explain why Einsteins general relativity theory is important to the makers of GPS system

How did people years ago find out which side of a magnet was north and which was south?

How do the weights of the tug of war teams affect the match

An insulated cup contains 75g of water at 24 degrees. A 26g sample of metal at 82.25 degrees is added. The final temperature of the water and metal is 28.34 degrees. What is the specific heat of the metal?

When a river flows into an ocean, it slows down and deposits materials in its alluvial fan/delta

If an ice cube melts at 0°C but water freezes at 0°C what is the difference between melting and freezing in terms of energy involved with phase changes and be particles of substances during the phase changes?

Why do the upper levels of Neptune's atmosphere appear blue?

An athlete has a mass of 62 kg and a volume of 65 liters. What is the density is kg/l?

A wave has a speed of 50m/sec if its frequency is 100 hz what's it's wavelength

11. A depression in the ground due to a cave collapse or acidic water dissolution of limestone is called a A. sinkhole. B. stalagmite. C. stalactite. D. cave.