Classical Mechanics and Special Relativity

what are the two different coefficients of friction

µ_s = coefficient of static friction
µ_k= coefficient of kinetic friction

how to turn the gravity equation into a vector equation

add in - “r hat”
ie the unit vector in the direction towards the affected object

what is Newton’s Shell Theorem

• inside the hollow sphere, there is no gravitational effect

• outside the sphere, the sphere acts as a point mass at the centre of the sphere with the same mass

what is the sum of all internal forces in a body and why

0, due to Newton’s 3rd Law ie equal and opposite

for a body made up of particles, how does F=ma apply to the body

F=ma is only true for the centre of mass of the body

how to find the centre of mass for a continuous body

r_cm=(∫r dm) / (∫dm)
where dm is an infinitesimally small mass and r is a position vector

how to find ∫r dm

find ∫x dm, ∫y dm, ∫z dm