Motion and Forces Chapter 1 Study Guide

What is motion?

Motion is a change of position over time.

What is the relationship between velocity and acceleration?

Acceleration is the change in velocity over time.

List four ways an object can accelerate.

1. Increase speed. 2. Decrease speed. 3. Change direction. 4. Change both speed and direction.

List two examples of an object not accelerating.

1. Not moving. 2. Move at constant speed in a straight line.

What is a reference point?

A reference point is a location to which you can compare other locations.

Give an example of a velocity.

A train going north at 100 miles/hour.

How do you know that an object has moved?

An object has moved if its position changes over time.

From the distance-time graph, calculate the speed from 0 minute to 6 minutes.

Divide 3 miles by 6 minutes. Speed is 0.5 miles/minute.

From the distance-time graph, calculate the average speed for the entire trip.

Divide 4 miles by 20 minutes. Average speed for the trip is 0.2 miles/minute.

How can you calculate average speed?

Divide the total distance by total time.

What is a frame of reference?

Frame of reference is the location of an observer of a motion.

On a distance-time graph, how would an object reversing direction appear?

It would appear as a falling line.

On a distance-time graph, how would an object with zero speed appear?

It would appear as a flat, horizontal line. (from B to C)

On a distance-time graph, how would an object moving in constant speed appear?

It would appear as a rising line.

What do you need to know to measure an object's position?

Object's distance from a reference point.

On the velocity-time graph, identify different types of acceleration.

Part A represents positive acceleration. Part B represents zero acceleration. Part C represents negative acceleration.

A person on a moving train sees a car that appeared to be stopped. A person outside the train sees both the car and train moving. This example shows...

Relative Motion

What is speed?

Speed is how fast positions change with time.

Car's speedometer shows that the car's speed is 60 mph. Is this instantaneous or average speed?

Speedometer shows the car's instantaneous speed.

A moving car experiences positive acceleration. What would be true of the values for initial velocity and final velocity?

The value of final velocity would be greater than the value of initial velocity. "Speed increases"

A moving car experiences negative acceleration. What would be true of the values for initial velocity and final velocity?

The value of final velocity would be less than the value of initial velocity. "Speed decreases"

A moving car experiences zero acceleration. What would be true of the values for initial velocity and final velocity?

The values for initial velocity and final velocity would be the same. "Speed remains constant"

From the distance-time graph, determine the total distance and total time for the trip. Then find the average speed for the whole trip.

Total distance = 2 + 0 + 2 + 0 + 4 = 8 miles Total time = 20 minutes Average speed = 8 miles/20 minute = 0.4 miles/minute

What is velocity?

Velocity is speed plus direction.

A person on a moving train and a person outside the train observe different motion because each person has...

different frame of reference.

To find the speed of an object in motion, you need to measure...

distance and time

What is instantaneous speed?

moment-by-moment speed