# Tutor profile: Taylor W.

## Questions

### Subject: Physics (Thermodynamics)

Explain the difference between Newton's First Law for an open and a closed system.

In the case of a closed system, mass is fixed, so there is no mass flow rate. Therefore, the first law equation for a closed system is simply the change in internal energy, U, is equal to the heat transfer into the system minus the work done by the system. The open system on the other hand requires the mass flow rate to be summed over the inlets and exits, and often includes changes in potential energy, kinetic energy, and enthalpy as well.

### Subject: Pre-Calculus

How do you find the area of a right triangle given two side lengths?

First, solve for the third side using Pythagorean Theorem, and then plus into the area equation for a right triangle (i.e. one-half base multiplied by height).

### Subject: Calculus

What is the difference between a derivative and an integral?

A derivative is equal to the slope of a curve at a point. An integral is the area under a curve for a given interval. Also, a derivative will decrease the magnitude of the power, whereas an integral will increase the magnitude of the power.

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