Specific Heat Capacity

 

Specific heat capacities are SPECIFIC to certain types of substances. If you have something that is changing temperature you have a specific heat capacity measured in J/gºC. However, if something is not changing temperature (freezing/boiling point or on fire) then you have units measured in J/g (or J/mol).

Heat Transfer

 

Energy Conservation

 Mechanical Energy = potential + kinetic. 

Objects moving up and down turn their PE-->KE and KE-->PE

Types of Forces - Freebody diagrams

 

These are the forces we'll be using as we label our Free-body diagrams:

In each diagram, identify the type of force by adding a subscript. These are vectors, so the length of the arrows drawn matters!

Start in the center and point outwards!

In diagrams where something is on a ramp, keep in mind some key rules:
Gravity always goes straight down towards the center of the earth.
Normal force, or the oppositional force of a surface, is perpendicular to the surface. The ground in holding the bike up (straight up from itself), it's not pushing sideways.

This means that the force that is opposing the normal force is a component vector of gravity.

Assumed Values

In physics story problems, there are often assumed values that are hidden in the story. They are a word, phrase, or implied idea that is supposed to give you a number to be used in your equations. 

For motion in one dimension: 

• Starting or ending from rest:  vi or vf = 0m/s
• If something is dropped:  vi=0m/s
• If something gets the the maximum height:  vf = 0m/s (it's not moving up or down at the top of the flight)
• If you are on earth going up and down: a=9.8 or 9.80m/s/s

For 2D motion:

This means ax=0m/s/s while ay=9.8m/s/s

The speed at the top is only the horizontal component

2D Motion Concepts

When thinking about motion that's happening in two dimensions, you need to think about the two components separately. 

This means, you want to divide up your acceleration, velocity, and distance values into x and y. 

Do not put x & y values together in the same kinematic equation. The only value that counts for both x and y is time. 

Because gravity affects vertical, a in the y direction = g = 9.8 or 9.80m/s/s

The acceleration in the x direction is zero! Notice in each of the pictures, the velocity in the x direction is constant. The overall velocity will increase and decrease, but it's the y that is changing not the x.

 

Unit Conversions

 Use equalities or how many ___ fit inside of ___ in order to cancel units. This is called dimensional analysis. Your goal is to get rid of the units that you don't want and get to the units you do want. 

Velocity Graph Notes

 

Motion Graphs - Memorize!

Number Rules

Powers of 10



Scientific Notation


Significant Digits

Prefixes