Final answer:
To find potential energy with mass in pounds and height in miles, you must first convert to kilograms and meters respectively. Then use the equation PE = mgh where m is the mass, g is the acceleration due to gravity, and h is the height. Units of potential energy are joules.
Step-by-step explanation:
To find the potential energy of an object in a gravitational field when given mass in pounds and height in miles, you would first need to convert these units to a consistent set, typically kilograms for mass and meters for height, as the standard unit of potential energy is joules (J).
As an example, to calculate the potential energy of a 1360 kg automobile parked on a 36.6 m (120 ft) high parking garage, we use the formula PE = mgh, where m is the mass of the car, g is the acceleration due to gravity (9.81 m/s²), and h is the height above the reference point (street level).
The units of potential energy are joules (J), the same as for kinetic energy. In the example, the potential energy is calculated to be PE = 4.88 x 10² kJ.