Name: ______________________

UNIT 2: PHYSICS

Topic 2: Uniform Motion & Speed

Uniform Motion

Any object that travels in a ________________________ at a ___________________________ is said to have uniform motion…

● E.g. does the bowling ball pictured to the right travel with uniform motion?

● Is it possible to move with uniform motion for extended periods of time?

Average Speed

The average speed of an object may be determined by comparing the distance travelled by said object to the time required to travel that distance:

- SCIENCE 10H -

Name: ______________________

Note: Calculations of average speed assume that an object is moving with uniform motion. PRACTICE1. A vehicle travels a distance of 120 km over a period of 1.5 h. Calculate

the average speed of the vehicle.

2. A tsunami travels a distance of 4.0 x 106 m over a period of 36000.0 s. Calculate the average speed of the tsunami.

3. Convert the average speed of the tsunami determined in question #2 into km/h.

4. A plane flies at an average speed of 694 m/s. Calculate how long it would take the plane to fly around the world, a distance of approximately 4.00 x 107 m.

5. A train travels at an average speed of 6.9 m/s for a period of 160 s. Calculate distance travelled by the train.

- SCIENCE 10H -

Name: ______________________

Distance vs. Time Graphs

The average speed of an object travelling with uniform motion can be graphed by plotting the ___________________ it travels vs. the _______________ required to travel said distance…

● How can we use this information to help predict the distance travelled

after 12 s?

● What does the slope of the line represent?

● What is the formula used to calculate slope?

- SCIENCE 10H -

Name: ______________________

PRACTICE #1a. Examine the following graph. Which object is moving the fastest? How

do you know?

b. Calculate the average speed of objects A, B and C.

- SCIENCE 10H -

Name: ______________________

PRACTICE #2Describe the motion of the object pictured below at each of the following points:A =

B =

C =

D =

- SCIENCE 10H -

Name: ______________________

PRACTICE #3a. Create a distance-time graph to represent the motion of the following

object:

Time (s) Distance travelled (m)

0.0 0

2.0 10

4.0 20

6.0 30

8.0 40

10.0 ?

- SCIENCE 10H -

Name: ______________________

b. Calculate the object’s average speed.

- SCIENCE 10H -

Name: ______________________

c. Determine the distance travelled by the object after 10.0 s.

Speed vs. Time Graphs

Speed-time graphs may be used to confirm that an object is travelling with uniform motion:

PRACTICE #1Examine the graph below. Describe the motion of the bus from points… O-A =

- SCIENCE 10H -

Name: ______________________

A-B =

B-C =

C-D =

D-E =

E-F =

PRACTICE #2The area under a speed-time graph represents the distance travelled by the object…

a. Calculate the distance travelled by objects A, B, and C in the graphs below.

- SCIENCE 10H -

Name: ______________________

b. Which object travelled the furthest?

PRACTICE #3The following data was collected for an object travelling with uniform speed:

Time (s) Speed (m/s)

0.0 9.8

1.0 10.0

- SCIENCE 10H -

Name: ______________________

2.0 10.2

3.0 10.0

4.0 9.9

5.0 10.1

a. Draw a speed-time graph for the data.

- SCIENCE 10H -

Name: ______________________

b. Determine the slope of the line. How does this tell us that the object is moving with uniform speed?

c. Determine the area under the line for the time interval 0.0-5.0 s. What does this value represent?

- SCIENCE 10H -