Physics 1510: Unit 1
1.1: Standard of length, mass and time
• Fundamental units of length is meters
o The meter is the distance travelled by light in a vacuum during a time
interval of 1/299 792 458 second
• Fundamental unit of mass is kilogram
o The kilogram is defined as the mass of a specific platinum iridium alloy
cylinder kept at the international Bureau of weights and measures at
• Fundamental unit of time is second
o The second is defined as 9 192 631 700 times the period of oscillation of
radiation from the cesium atom
o Micro 10 symbol μ
o Milli 10 symbol m
o Kilo 10 symbol k
o Mega 10 symbol M
1.2: The building blocks of matter
• 1 kg is approximately equal to 2 lb
• Inside the nucleus of an atom there are protons and neutrons.
• Protons and neutrons are composed of quarks
• Protons consist of 2 up quarks and 1 down quark
• Neutrons consist of 2 down quarks and 1 up quark
• The up quark carries a positive charge of +⅔
• The down quark carries a negative charge of -⅓
• A proton has a net charge of +1
• A neutron has a net charge of 0
• Water molecules are composed of two atoms of hydrogen and one atom of
oxygen. The hydrogen atoms contain 1 electron each, and the oxygen atom brings
eight electrons. The resulting molecule (H 2) contains ten electrons.
• The nucleus of the deuterium only contains one neutron and one proton in it.
• No, electrons are not made of quarks, like protons and neutrons, because electrons
are leptons and are not known to be composed of any sub particles.
• The diameter of an atom ranges approximately from 0.1 to 0.5 nanometer.
1.3: Dimensional Analysis
• Quantities can only be added or subtracted if the have the same quantities
(example: kg, s, m)
• Velocity [v]= L/T (Length divided by time)
[v] = at (Acceleration multiplied by time)
• Area [a]= L 2
• Acceleration [a]= L/T 2
• Distance travelled given that you DID NOT start from rest x=at
• Distance travelled given that you DID start from rest x= ½at 2 1.4: U