The main light gathering device of a refractor telescope is

How is energy transferred and conserved

Which wave source can travel through the vacuum of space?

If a ball is given an initial speed of 15 m/s on a horizontal, frictionless surface, how fast will the ball be rolling in 5 seconds?

Roger sees water balloons fall past his window. He notices that each balloon strikes the sidewalk 1.2s after passing his window. Roger's room is on the fifth floor, 25m above the sidewalk.

Two electrons exert a force of repulsion of 1.2 N on each other. How far apart are they? The elementary charge is 1.602 * 10-19 C and Coulomb's constant is 8.987 * 109 N · m2/C2. Answer in units of m.

Most of the Earth's volcanoes occuWhen fossils or minerals form, certain unstable elements are sometimes locked into them.

a man is standing on the edge of a 20.0m high cliff. he throws a rock vertically with an initial velocity of 10.0m/s. how high does the rock go?

The slope of a velocity time graph over any interval of time gives the during that interval

if light travels in a vacuum at 3.00 x 10^8m/s and its frequency is 7.44 x 10^7 what is its wavelength

the half-life of carbon - 14 is 5730 years. What fraction of carbon-14 would remain after 11,460 years?