2) Using the lab equipment and a calculator, compute the density and identify the mineral in question.
Mineral Densities
Mineral Density (gm/ml)
Potash alum 1.75
Hornblende 3.0
Zircon 4.7
Phosgenite 6.0
Galena 7.2
Platinum 21.45

A) galena
B) platinum
C) phosgenite
D) potash alum

PLEASE HELP ME PLEASSEE

Given the position vector of the particle r(t)=(t+1)i+(t^2−1)j+2t k, find the particle's velocity and acceleration vectors at t=1

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.

He latent heat of vaporization for ethyl alcohol is 854 j/g. the amount of energy, rounded to the nearest whole number, needed to change 5.20 grams of ethyl alcohol from a liquid to a gas is