Coins were developed as a medium of exchange because other items like cows, grain, and land were more difficult to move from place to place.

A red apple will appear black when illuminated with

Which two gases in the atmosphere are essential to life on Earth? * Nitrogen and Helium Oxygen and Carbon Dioxide Neon and Argon Hydrogen and Helium

Which is an application of the principle of uniformitarianism? A. ordering a group of fossils from largest to smallest B. examining a rock to find out what minerals are in the rock C.

A 1400 kg wrecking ball hangs from a 20-m-long cable. the ball is pulled back until the cable makes an angle of 30.0 ∘ with the vertical. part aby how much has the gravitational potential energy of the ball changed?

The planet Krypton has a mass of 8.4 x 1023 kg andradius of 3.4 x 106 m. What is the acceleration of an object in free fall near thesurface of Krypton? the gravitational constant is 6.6726 x10-11 N x m2 / kg2. Ans. in unitsof m/s2.

An empty capacitor is connected to a 12.0 V battery and charged up. The capacitor is then disconnected from the battery, and a slab of dielectric material (dielectric constant "k" = 2.8) is inserted between the plates.

how long can you afford to stop for lunch if you can drive a steady 90 km/h on the highway and must take a 225 km trip in 210 min?

Which layer of the Sun's atmosphere is farthest from the surface of the Sun? A) troposphere B) corona C) chromosphere D) photosphere

Which of the following is a supersonic speed? Mach 0.005 Mach 0.05 Mach 0.5 Mach 5

How do you solve this equation ___ Al + ___ Na1 O1 H1 - ___Na3 Al1 O3 + __ H2