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What is acceleration? Chapter 1 lesson 3

acceleration is the rate which velocity changes. in other words the process of speeding up.

In science, acceleration refers to increasing speed, decreasing speed, changing direction.

Changing Speed:

Whenever an object changes it speed, the object is accelerating.

Just as objects can speed up they can also slow down and is known as de-celarating.

Changing Direction:

Acceleration can be a change in direction as well as speed.

Many objects will continuously change direction without changing its speed.

Calculating Acceleration:

Acceleration describes the rate which velocity (speed) changes.

to determine the acceleration of an object moving in a straight line, you calculate the change in speed per unit of time.

Formula for finding acceleration: Final speed - initial speed/ time

The SI unit of acceleration is kilometers per second.

How do you graph Acceleration?

You can use both a speed-versus-time graph and a distance-versus-time graph to analyze the motion of an accelerating object.

When is an object in motion? Lesson 1

motion is if its position changes relation to another object.

because your position relative to your chair does not change, you could say that you are not in motion.

Reference Points:

A reference point is a place or object used for comparison to determine if something is in motion.

An object is in motion if it changes position relative to a reference point.

Relative Motion:

Earth moves around the sun at a speed of about 30 kilometers every second.

Measuring Distance:

Science use a system of measurement called the International System of Units also known as the SI unit.

Distance is the length of the path between two points.

Scientists use other units to measure distance distances much smaller or much larger than a meter.

centi: means one-hundreth

milli: means one-thousand

How do you calculate speed? Lesson 2

The speed of an object is the distance the object moves per unit of time.

Speed is a type of rate.

The speed Equation:

To calculate the speed of an object, divide the distance the object travels by the amount of time it takes to travel that distance.

Formula for Speed: Speed= distance/time

The speed equation contains a unit of distance divided by a unit of time.

the speed of an airplane is much greater than the speed of a snail because the airplane travels much farther than the small in the same amount of time.

Average Speed:

Average Speed is when you divide the total distance traveled by the total time.

Instantaneous Speed is the speed at which an object is moving at a given instant time.

It is important not to confuse it with average speed.

How do you describe velocity?

to describe an objects motion, you need to know the direction.

When you know both the speed and direction of an object's motion, you know the velocity of an object.

Velocity is a given direction. (speed)

How do you graph motion?

You can show the motion of an object on a line graph in which you plot distance versus time.

The steepness of a line on a graph is known as a slope.

The slope explains how fast one variable changes in relation to other variable in the graph.

the slope tells you the rate of change.

Calculating Slope:

Calculate by dividing the rise by the run. the rise is the vertical difference between any two points on the line.

Formula for Slope: Rise/run

Different Slopes:

The slope of each segment is different. From the steepness of the slopes you can tell that the jogger ran fastest during the third segment.