Chapter 1

Seite 1

Law of Conservation of Energy

1. Energy is neither created or destroyed

The potential energy of the weight (as an object falls) becomes kinetic energy as the weight accelerates toward the ground.

Energy can change from one type to another, but the total quantity of energy remains the same.

2. The tendency of systems with high potential energy to change in a way that lowers their potential energy.

Objects/systems with high potential energy tend to be unstable.

Likewise, for chemical substances, energy remains concentrated in the molecules until they undergo a chemical reaction which release the potential energy. The release of this potential energy make the molecules more stable.

Seite 2

Mass vs Weight

The mass of an object is a measure of the quantity of matter within it vs.

The weight of an object is a measure of the gravitational pull on its matter.

Gravitational pull varies per planet, but the mass remains the same.

Seite 3

Significant Figure Principles

1. All nonzero digits are significant.

2. Interior zeroes are significant.

3. Leading zeroes are not significant.

Trailing zeroes:

1. After a decimal are always significant.

2. Before a decimal point, after a non-zero digit, are always significant

3. Before an implied decimal point are ambiguous and avoided using scientific notation.

Seite 4

Calculating with Significant Figures

Multiply & Divide: use the factor with the least significant figures.

Add & subtract: carries the same number of digits after the decimal place as the value with the least digits after the decimal

Seite 5

Precision & Accuracy

Precision: how close a series of measurements are to one another/ how reproducible they are

Accuracy: how close the measured value is to the actual value

Seite 6

Order-of-Magnitude Estimations

1. If the digit is less than 5, it remains the same. ex: 4.36 * 10^5 = 10^5

2. if the digit is more than 5, add a multiplier of 10. ex: 6.1101 * 10^-3 = 10^-2