What was the total weight (lbf) of chocolate in the vat? the specific gravity of chocolate is approximately 1.24?

I believe this question is missing some information, but I'll just tell you how to solve it and you can apply using the information you have.

First, we have the specific gravity which is the ratio between the density of the substance to the density of water at 4 degrees celcius (1000 kg/m^3)
specific gravity of milk = density of milk/density of water
1.24 = density of milk/1000
density of milk = 1240 kg/m^3

Then we have:
density = mass/volume
I believe the question should have any information regarding the volume.
You will use this information to calculate the mass of milk in kg.

Then, you will change the kg to pound (lb) using cross multiplication. 
(1 kg = 2.2 lb).

The last step is to calculate the weight in lbf. To do this, you will simply multiply the mass (in lb) by the gravity (9.8 m/s^2)

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

Not what goes around on earth but the universe too.