Cheatography

# Basics of Physics Cheat Sheet (DRAFT) by pastel-galaxies

A cheat sheet explaining the basic rules of physics, including standard units, an overview of units, and important formulas to know

This is a draft cheat sheet. It is a work in progress and is not finished yet.

### Key Words

 Often we are given inform­ation from the wording of the problem that is not directly stated. For example, if a problem tells us that an object started from rest, we know that the initial velocity is zero, even though the problem didn't say anything about velocity. If a problem says... It is really telling us about... Beginning Starti­ng/­Initial Velocity From ... to ... Starting at ... and stopping at ... From rest Initial velocity (VI) Reaches Final (velocity, sometimes) Freely falling Gravity

### Scalar vs. Vector

 A scalar is a quantity that has a magnitude only. A vector is a quantity with a magnitude and a direction. Scalar Vector 8 years old 10 kilometers east 14 days 12 miles west 3 meters 2 inches south 8 apples 5 yards north

### Conversion Tables

 1 kilometer 1000 meters 1 centimeter 0.01 meter 1 gram 0.001 kilogram

### Standard Units in Physics

 There are specific units that you must use when solving physics problems. If your final answer uses units other than these, it will be marked wrong. Measur­ement Unit Abbr. Distance meters m Displa­cement meters m Velocity meters­/second m/s Accele­ration meters­/second2 m/s2 Force* newtons N Weight newtons N Mass kilograms kg Time seconds s Work joules J Gravity** meters­/second2 9.8 m/s2
*: see force box below for everything measured in newtons.
*: Gravity will always be 9.8 m/s2 unless a problem specif­ically mentions a zero-g­ravity enviro­nment (rare but possible).

### Types of Force

 There are several types of forces that are all measured in newtons. It is important to remember that every force is equal to mass times accele­ration, but certain forces have easier ways of measuring them. FG Force of gravity Mass × gravity FD Driving force FG sin θ FF Force of friction μ × FN FN Normal force FG cos θ
The website I made this cheat sheet on doesn't have a subscript option (the little letters used for things like initial velocity) so I put it in supers­cript instead. However, you will see it in subscript on the test, so be aware.

### Formula List

 Every formula you'll need for the class should be here! Area of a rectangle length × width Area of a triangle ½ length × width Area of a trapezoid ½ (b1 + b2) × height Distance speed × time Speed distance / time Weight (FG) mass × gravity Force (general) mass × accele­ration FD FG × sin θ FN FG × cos θ FF μ × FN Work Force × displa­cement Kinetic energy ½ mass × velocity2 Potential energy mass × gravity × height Centim­eters to meters cm × 0.01 Kilometers to meters km × 1000 Accele­ration VF - VI / TF - TI

### Kinematic Formulas

 Δx = VF2 - VI2 / 2a No t VF = VI + at No Δx Δx = VIt + ½at2 No VF Δx = (VF + VI / 2) × t No a