What is a gravational lens?

A color television tube generates some X-rays when its electron beam strikes the screen. What is the shortest wavelength of these X-rays, in meters, if a 31 kV potential is used to accelerate the electrons?

How are metamorphic rocks like igneous rocks? How are they like sedimentary rocks?

Venus has an average distance from the sun of 0.623 AU. How long does it take Venus to complete one orbit around the sun?

Space walking astronauts are usually tethered by rope to the space capsule. An astronaut wearing his spacesuit and a 50 kg backpack has had his tether come loose and is now slowly drifting away into space.

2 clues about a chemical change

A hole of radius r is bored through the center of a sphere of radius r. Find the volume v of the remaining portion of the sphere.

What is a sentence for refraction

A stimulus with a low predictive value means that

In otherwise empty space is a system of 4 particles, each of the same mass. The accelerations of the particles are as follows: a1 = ˆi a a2 = ˆj a 2 a3 = - (ˆi + ˆj) (2 a) a4 = (ˆi - ˆj) (3 a), where a > 0 is a constant.

How many electrons does a neutral atom of oxygen-18 have? 8 O 16.00 A. 8 B. 10 C. 18 D. 16