An electrical short cuts off all power to a submersible diving vehicle when it is a distance of 29 m below the surface of the ocean. The crew must push out a hatch of area 0.950 m2 and weight 390 N to escape.
If the pressure inside is 1.0atm, what downward force must they exert on the hatch to open it?

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.

Amplify and switch electrical power and electronic signals

Independent variable is something that is changed in a experiment. 

The sample with the lowest specific heat capacity will have the greatest temperature increase. in this case, it would be platinum.