What are quarks?
Quarks are the building blocks of protons and neutrons, as found in the nucleus of atoms. They are as far as we know, fundamental particles, but this could change in the future. There are 6 types, named up, down, strange, charm, top and bottom; each having it's own mass, charge and spin.
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Related Physics A Level answers
All answers ▸What is gravitational potential and how can gravitational potential energy be used to estimate the escape velocity of a planet of mass m and radius r?
What is Olbers' Paradox?
An ideal gas at a temperature of 22 C is trapped in a metal cylinder of volume 0.2 m^3 at a pressure of 1.6x10^6 Pa. The gas has a molar mass of 4.3 x 10^(-2) kg mol^(-1). Calculate the density of the gas in the cylinder.
Using Newton's law of universal gravitation, show that T^2 is proportional to r^3 (where T is the orbital period of a planet around a star, and r is the distance between them).