Work and Energy - Mission WE3 Detailed Help

Which of the following variations will increase the potential energy of an object?

The potential energy is the energy stored in an object due to its vertical position above (or below) the ground or some zero level. The amount of potential energy (PE) possessed by an object depends upon its mass (m) and its height (h). The formula for calculating the potential energy is
PE = m • g • h

where g is the gravitational field strength (9.8 N/kg on Earth).

The formula for potential energy is stated in the Formula Frenzy section above. As expressed by the equation, potential energy depends upon the mass and the height of the object. Any increase in these two quantities will lead to an increase in the amount of potential energy possessed by the object.

Many students become confused by height, speed, and potential energy. Potential energy is simply the energy stored in an object due its vertical position. The higher an object is raised, the more potential energy which it possesses. Often times (but certainly not always) an increase in height corresponds to a decrease in speed. So some gain the impression that a decrease in speed will always lead to an increase in height. But don't be fooled! This type of thinking is not correct. First, it puts the cart before the horse (or the effect before the cause). It is an increase in the height that causes the decrease in speed (when they do correspond to each other). And second, it is simply not always true that the change in height leads to a change in speed. It is possible for an object to decrease its height at a constant speed - for instance, when climbing down a flight of stairs or descending on an elevator. In the end, the only two variables which can be used to evaluate whether or not the potential energy has increased are the variables of mass and height.