An unknown substance has a mass of 15 g and a volume of 4 cm3. Calculate the density of the unknown substance.

1. Which part of a compressional wave has the lowest density?

What is difference between atoms and molecules?

Pick the best description of energy efficiency. A. Efficiency is equal to the ratio of energy you put in to the energy you get out. B. Efficiency is equal to the ratio of energy you get out to the energy you put in. C.

Which of the following correctly describes isotopes of the same element? A.) Atoms that have the same number of protons but a different number of electrons. B.) Atoms that have the same number of protons but a different number of neutrons. C.

Which statement describes the daily motion of the moon? rises and sets at same time rises and sets 50 minutes later rises 50 minutes later, sets 50 minutes earlier rises 50 minutes earlier, sets 40 minutes later

How big is a wifi pulse signal coming from your router? A) 10 meters B) 15 meters C) 5-10 meters D) 20-30 meters

Imagine you are in a music concert. What different sounds might you hear? How are these sounds made?

Dose aloe Vera grow in the mesa?

A tradesman sharpens a knife by pushing it against the rim of a grindstone. The 35 cm diameter stone is spinning at 200 rpm and has a mass of 28 kg. The coefficient of kinetic friction between the knife and the stone is 0.20.

What is the unit for force we use when calculating F=ma?