1.3 Velocity-time Graphs

Question 1

What is the formula for calculating the slope of a velocity-time graph?

Answer 1

slope = rise/run

Where rise is the change in velocity (Δv–>) and run is the change in time (Δt)

Question 2

What is the slope of the velocity-time graph in the given scenario?

A horizontal line at 4 km/h.

Answer 2

0 km/h²

Indicates there is no change in the plane’s velocity

Question 3

What does a slope of zero in a velocity-time graph indicate about the object’s motion?

Answer 3

The object’s velocity is constant

There is no acceleration

Question 4

What are the units of the slope of a velocity-time graph?

Answer 4

km/h²

m/s²

These units are also units of acceleration

Question 5

What is the standard unit for acceleration in physics?

Answer 5

metres per second squared (m/s²)

This unit represents distance divided by time squared

Question 6

Fill in the blank: Acceleration values can be recognized by their units, which are always _______.

Answer 6

units for distance divided by time units squared

Question 7

True or False: If an object is moving at a constant velocity, its acceleration is zero.

Answer 7

True

Constant velocity implies no change in speed or direction

Question 8

What is acceleration?

Answer 8

A vector quantity representing the change in velocity (magnitude or direction) per unit time.

Acceleration occurs when an object’s velocity changes over a time interval.

Question 9

What type of motion is described when an object’s speed or direction is changing?

Answer 9

Non-uniform motion.

Non-uniform motion indicates that the object is undergoing acceleration.

Question 10

What does it mean if an object is starting from rest and reaches a constant velocity?

Answer 10

The object undergoes acceleration during the time interval.

This means the object’s velocity changes from zero to a final non-zero value.

Question 11

What is the variable used to represent acceleration?

Answer 11

a–>

Acceleration is important in understanding the motion of objects.

Question 12

True or False: Acceleration can only be positive.

Answer 12

False.

Acceleration can be positive (increasing velocity) or negative (decreasing velocity).

Question 13

Fill in the blank: Acceleration is a _______ quantity.

Answer 13

vector

This means it has both magnitude and direction.

Question 14

What does a drag racer illustrate in motion?

Answer 14

Acceleration from rest to a constant velocity.

The drag racer example demonstrates how velocity changes over time.

Question 15

What does calculating the slope of a line or curve at a single point represent?

Answer 15

Finding an instantaneous value

Question 16

What does calculating the slope between two points represent?

Answer 16

Finding an average value

Question 17

Define tangent in the context of a curve.

Answer 17

A straight line that touches a curved-line graph at only one point

Question 18

What is instantaneous velocity?

Answer 18

The moment-to-moment measure of an object’s velocity

Question 19

How can you describe a trip using instantaneous velocities?

Answer 19

By recording the speed of your car once every second

Question 20

What is required to determine the velocity of an object from a position-time graph?

Answer 20

Calculating the slope of the position-time graph

Question 21

What does each point on a curve indicate?

Answer 21

The position of the object at an instant in time

Question 22

How do physicists determine the velocity of an object at any instant?

Answer 22

By using tangents

Question 23

What does each tangent on a curve represent?

Answer 23

The velocity at that instant

Question 24

What must be true for an object to have an instantaneous velocity at a certain position and time?

Answer 24

It must have an instantaneous velocity equal to the slope of the tangent at that point

Question 25

What do determining the slopes of the tangents at different points on a position-time curve provide?

Answer 25

The instantaneous velocities at different times

Question 26

Fill in the blank: A tangent is a straight line that touches a curve at only one _______.

Answer 26

point

Question 27

True or False: Instantaneous velocity can be derived from the average velocity.

Answer 27

False

Question 28

Fill in the blank: To find the instantaneous velocity, physicists use _______.

Answer 28

tangents

Question 29

What is the slope of a position-time graph?

Answer 29

Velocity ## Footnote The slope indicates how position changes over time.

Question 30

What do the slope values of position-time graphs represent?

Answer 30

Instantaneous velocities at given times ## Footnote These values are used to create a velocity-time graph.

Question 31

What type of graph is created using the slopes of position-time graphs?

Answer 31

Velocity-time graph ## Footnote The graph indicates the change in velocity over time.

Question 32

What does it mean if a velocity-time graph is a straight line that goes through the origin?

Answer 32

The dragster has started from rest (0 velocity) ## Footnote This indicates the initial condition of the motion.

Question 33

What does a positive slope on a velocity-time graph indicate?

Answer 33

The object is undergoing uniformly accelerated motion ## Footnote This implies a constant acceleration.

Question 34

What are the units of the slope of a velocity-time graph?

Answer 34

m/s² ## Footnote These units represent acceleration.

Question 35

What is uniformly accelerated motion?

Answer 35

Constant change in velocity per unit time ## Footnote This describes motion where acceleration remains constant.

Question 36

True or False: If the velocity-time graph has a non-zero slope, the acceleration is constant.

Answer 36

True ## Footnote A straight line on the velocity-time graph indicates constant acceleration.

Question 37

Fill in the blank: When jet fighters come in to land on an aircraft carrier, they stop so quickly that pilots sometimes lose _______.

Answer 37

Consciousness ## Footnote This is due to the enormous acceleration experienced during landing.

Question 38

What can happen to pilots when they eject from an aircraft?

Answer 38

They can lose consciousness due to enormous acceleration ## Footnote This is similar to the experience during rapid deceleration in landings.

Question 39

What does negative acceleration mean?

Answer 39

It indicates that the acceleration value is negative, but it does not necessarily mean the object is slowing down.

Question 40

How should you interpret the sign of acceleration?

Answer 40

You need to compare it to the sign of velocity.

Question 41

What happens when the directions of velocity and acceleration are the same?

Answer 41

The object is speeding up.

Question 42

In the case of a drag racer speeding up, how are velocity and acceleration related?

Answer 42

The direction of its velocity is the same as the direction of its acceleration.

Question 43

Fill in the blank: When the directions (signs) of velocity and acceleration are ______, the object is speeding up.

Answer 43

[the same]

Question 44

True or False: Negative acceleration always means an object is slowing down.

Answer 44

False