What two factors does sonar use to determine ocean depth?

What is the conversion factor between kg/m^3 and g/m^3. express your experimental values for the densities in kg/m^3.

Determine the amount of work done when a crane lifts a 100-n block form 2m above the ground to 6m above the ground

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)