Concepts of Motion

Question 1

What is motion?

Answer 1

When an object changes its position.

Question 2

What are the four basic types of motion?

Answer 2

Linear, circular, projectile and rotational

Question 3

What is the trajectory of an object?

Answer 3

The path along which the object moves.

Question 4

What is a motion diagram?

Answer 4

A photo or diagram that shows an object’s position at several equally spaced time intervals. (Time not given usually)

Question 5

What does a motion diagram of an object at rest look like?

Answer 5

There appears to only be one image.

Question 6

What does a motion diagram of an object moving at a constant speed look like?

Answer 6

There are equal spaces or distance between each image.

Question 7

What does a motion diagram of an object that is speeding up look like?

Answer 7

The space between images appears to increase.

Question 8

What does a motion diagram of an object that is slowing down look like?

Answer 8

The space between images appears to be decreasing.

Question 9

What is a particle?

Answer 9

A single point in space that has no size, shape, top, bottom, front or back.

Question 10

When does the particle model not apply?

Answer 10

For rotating or spinning objects.

Question 11

Can time be negative?

Answer 11

Yes, as t = 0 is just a reference to the coordinate system.

Question 12

What are scalar quantities?

Answer 12

A quantity that can be described by a single number or magnitude.

Question 13

What are vector quantities?

Answer 13

A quantity that requires both magnitude and direction.

Question 14

What is a position vector?

Answer 14

A vector that extends from the origin to the position of the object. (r)

Question 15

Is the origin fixed or can it be moved?

Answer 15

No, the origin can be placed anywhere that is helpful.

Question 16

What is displacement?

Answer 16

The change in position of an object. Displacement = Final position - Initial position

Question 17

What is the displacement vector?

Answer 17

The vector that extends from the first point to the second point.

Question 18

Is position dependent on the coordinate system?

Answer 18

Yes.

Question 19

Is displacement dependent on the coordinate system?

Answer 19

No, it will always stay the same.

Question 20

How do you add vectors?

Answer 20

You add the tip of one vector to the tail of the other vector in order to obtain the resultant vector.

Question 21

How do you subtract vectors?

Answer 21

You add the negative vector (of the one being subtracted) to the tip of the first vector in order to find the resultant vector.

Question 22

Can change in time be negative?

Answer 22

No, time always proceeds forward.

Question 23

Is change in time dependent on the coordiate system?

Answer 23

No, the net change in time will always remain the same.

Question 24

Can displacement be negative?

Answer 24

Yes, it is possible to have a net movement in the negative direction.

Question 25

What is distance?

Answer 25

The total path length that is travelled by the object. (Scalar)

Question 26

What is average speed?

Answer 26

Total Distance / Time Interval

Question 27

What is average velocity?

Answer 27

The rate at which an object changes its position. Displacement / Time interval

Question 28

Does instantaneous speed equal the magnitude of instantaneous velocity?

Answer 28

Yes, when you take the limit as t \> 0, instantaneous speed and instantaneous velocity's magnitude are equal.

Question 29

What does a negative position indicate?

Answer 29

That the object is to the left or below the origin.

Question 30

What does a positive position indicate?

Answer 30

That the object is found to the right or above the origin.

Question 31

What does a negative velocity indicate?

Answer 31

That the object is travelling to the left or down.

Question 32

What does a positive velocity indicate?

Answer 32

That the object is travelling to the right or up.

Question 33

What is acceleration?

Answer 33

The change in an object's velocity. Change in Velocity / Time Interval

Question 34

What does a negative acceleration indicate?

Answer 34

That the object's is increasing its velocity to the left or down. NOT THAT THE OBJECT IS SLOWING DOWN.

Question 35

What does a positive acceleration indicate?

Answer 35

That the object's velocity is increasing to the right or up. NOT THAT THE OBJECT IS SPEEDING UP.

Question 36

What does it mean to have 0 acceleration?

Answer 36

The object is moving at a constant speed. (Which can be 0 also)

Question 37

What is the acceleration vector?

Answer 37

The vector that is the difference between two velocity vectors. (Change in velocity)

Question 38

What is required in a complete motion diagram?

Answer 38

The position of the particles, the velocity vectors and the acceleration vectors.

Question 39

If the velocity and acceleration vectors point in the same direction, what is the motion of the object?

Answer 39

It is speeding up.

Question 40

If the velocity and the acceleration vectors point in opposite directions, what is the motion of the object?

Answer 40

It is slowing down.

Question 41

What is required in a pictorial representation of the problem?

Answer 41

1. A motion diagram 2. Established coordinates. 3. Sketch (optional) 4. Defined symbols. 5. Knowns 6. Unknowns

Question 42

What is the four step method to solve physics problems?

Answer 42

Model - Assumptions Visualize - Pictorial Representation Solve - Use an equation Assess - Does this answer make sense?

Question 43

What is the SI unit for time?

Answer 43

Seconds

Question 44

What is the SI unit for length?

Answer 44

Meters

Question 45

What is the SI unit for mass?

Answer 45

Kg

Question 46

What is the SI unit for force?

Answer 46

Newtons, N = kg m / s²

Question 47

What is the SI unit for energy?

Answer 47

Joules, J = kg m² / s²

Question 48

How many significant figures does 300 have?

Answer 48

1

Question 49

How many significant figures does 300. have?

Answer 49

3