SOMEONE HELP QUICK! (question in the picture)

An object weigh 40n in air ,weigh 20n when submerged in water,and 30n when submerged in a liquid of unknown liquid density.what is the density of unknown of liquid?

While the change in blank will remain the same during a collision, the force needed to bring an object to a stop can be blank if the time if collision is blank

An electron is trapped at a defect in a crystal. the defect may be modeled as a one-dimensional, rigid-walled box of width 1.00 nm. (a) sketch the wavefunctions and probability densities for the n 1 and n 2 states. (b) for the n 1 state, nd the probability of nding the electron between x1 0.15 nm and x2 0.35 nm, where x 0 is the left side of the box. (c) repeat (b) for the n 2 state. (d) calculate the energies in electron volts of the n 1 and n 2 states