7th Grade Science Unit 2

Average Speed/Velocity

100

How is average speed calculated?

Distance/Time

200

Caleb is running around his neighborhood at a constant speed. He turns south and then west, before he makes it back home. He went the same speed the entire time. Did his velocity change?

yes, he changed direction

300

Students watched toy cars go down a ramp and recorded how far they went and how long it took. Which Toy Car had the greatest average speed?

Toy Car 1: 10 meters in 10 seconds

Toy Car 2: 20 meters in 12 seconds

Toy Car 3: 22 meters in 11 seconds

Toy Car 4: 21 meters in 7 seconds

Toy Car 4 was fastest at 3 m/s

400

*Question is on the board*

What is the total displacement for the Bus trip?

430 km

500

*Question is on the board*

The image is describing the movement of a city bus one afternoon. Calculate the average speed of the bus from point A to point C. (Be careful! Make sure you calculate the intervals first).

72.5 

HOW YOU SOLVE THIS MATTERS

Distance-Time Graphs

100

If I have a graph measuring a train's speed in meters per second, what is the y axis labeled? 

distance in meters

200

What does a downward slope mean on a Distance Time Graph? (line going down from left to right)

the object/person is going back toward the starting point

300

How far had Train A traveled when it stopped? How long had it stopped?

50 miles away, 1 hour

400

When were Train A and B the same distance away from their starting point?

3 hours

500

Calculate the average speed of both Trains from hours 3-5. 

Train A: 20 mph

Train B: 5 mph

Vectors & Forces

100

If Ms. Martin is spinning around in circles in her chair, but otherwise not moving, is her velocity constant or changing?

changing

200

If a book is lying flat on a desk, what forces are acting on it, if any?

gravity, table pushing up, air pressure, friction of table, etc.

300

Define a vector quantity.

any measurement with magnitude and direction

400

Ms. Martin and Ms. Tresca are playing Tug-o-War. Ms. Martin is pulling with 200 N of force, while Ms. Tresca is pulling with 250 N. Suddenly, Ms. Tresca quickly lets go. What will happen to Ms. Martin?

she will lunge backward and fall down

Newton's 1st Law

100

What is the other name for Newton's First Law of Motion?

Law of Inertia

200

If an object is flying through space, and its speed and direction remain unchanged, are these forces balanced or unbalanced?

balanced

300

Explain why airbags and seatbelts were invented using terms relating to Newton's First Law.

?

400

What are the two circumstances where we know that forces on an object are balanced?

no motion, or constant velocity (no changes)