Sonar is the detection of sound waves reflected off boundaries in water. a region of warm water in a cold lake can produce a reflection, as can the bottom of the lake. which would you expect to produce the stronger echo? explain.

Which of the following components of an electrical circuit is a source of voltage? A. a switch B. a battery C. a resistor D. a light bulb

Two ice skaters, with masses of 50 kg and 75 kg, are at the center of a 50 m - diameter circular rink. The skaters push off against each other and glide to opposite edges of the rink.

An upward force of 27.5 n is applied to a string to lift a ball with a mass of 2.5 kg. a. what is the net force acting upon the ball

Earths layers can be defined by their chemical composition. from surface to center, what are these layers? A) Continental crust, oceanic crust, mantle B) Lithosphere, asthenosphere, mantle C) Crust, mantle, core D) Asthenosphere, lower mantle, core

Quiz 2. In any energy transformation, energy is A destroyed B created C conserved ms 90%

How many earth years does it take mars to orbit the sun

Which represents a system that is almost completely closed?

If many household substances classify as acids or bases what is the ph scale

A protostar forms once the nebular cloud condenses and the core begins

How do whales bats and dolphins use echolocation? A To scare away predators B To attract mates C To orient them selves and find food D To tell animals of there species where they are