Forces and Motion

Forces

100

What is a force?

 A push or a pull

200

Name two NON-CONTACT forces.

gravity, magnetic, or electric

300

Name the 3 contact forces.

friction, normal, applied

400

Imagine 2 teams playing tug-of-war. How will one team win over the other team? (Describe the forces at work)

To win, one team would need to have a greater (unbalanced) applied force than the other team.

500

Explain why the moon orbits around Earth and not the sun. Use the words: "gravitational force", "mass" and "distance" in your answer.

Gravitational force is determined by two objects distance from each other and their mass. The moon is very close to Earth, so, even though the Sun is more massive, it revolves around the Earth.

Motion

100

Kinetic energy can be described as the energy of: ________

motion or movement

200

An unbalanced force acting on an object will result in:

the object moving

300

During which part(s) of this graph is motion occurring?

A, C and E

400

Calculate the net force of this free body diagram:

400 Down

500

Identify 3 types of forces acting in this picture. Describe whether it is balanced or unbalanced and what the net force is.

 Assume both people are pulling with 450 N of force.

Friction is occurring between their hands and the rope, and also between their feet and the ground. Applied force is occurring while they pull on the rope. Gravitational forces are pulling them towards the Earth. Normal forces are pushing the up against the ground.

The net force is zero, because they are pulling in opposite directions. This is a balanced force, meaning they are not moving.

Kinetic and Potential Energy

100

The more speed and mass an object has the _______ kinetic energy it has.

...more

200

Name 2 types of potential energy.

Possible answers:

gravitational, elastic, chemical, nuclear, thermal

300

The Law of Conservation of Energy states; energy...

Complete the Law.

energy cannot be created nor destroyed, only transformed

400

Describe kinetic and potential energy at point A of this pendulum.

At point A, kinetic energy is low (decreasing) and potential energy is high(increasing).

(Neither is at it's lowest or highest energy)

500

I. Identify when kinetic and potential energy are highest in the picture.

II. Describe the energy transformation occurring at letter (b) in the picture.

I. Kinetic energy is highest at letter (c) and potential is highest at letter (a).

II. At letter (b) potential energy is being transformed into kinetic energy as the cart gains speed.

Speed

100

What is the formula for calculating speed?

Rise/Run is also acceptable, since you can use that method to find the speed(slope) on a distance vs. time graph.

200

How far did this object travel?

4 km

(must include units for points)

300

Draw a simple distance vs. time graph that would represent a car slowing down and stopping at a red light. (no number lines necessary)

400

This is a distance vs. time graph of 2 peoples' performance in a race.

What is the average speed each runner ran? Who won the race?

The green runner averaged 20 km/h. The red runner averaged 10 km/h.

The green runner won the race because he went the same distance in less time. Also, because the green line is steeper.

500

Create a short story using the graph below. make sure to include details about her speed and how far she travelled.  The story starts like this: "Selena had to walk to her friend's house to give her a birthday gift..."

Many answers possible.

Challenge

100

What is the difference between repetition and replication in experimentation?

Repetition is when a scientist repeats their own experiment many times for accuracy.

Replication is when a scientist performs someone else's experiment for validity.

200

Between which two points was this object moving the fastest?

From C to D.

This line has the steepest, and mathematically largest slope.

300

In relation to other non-contact forces, what is unique about how gravitational forces move objects?

Gravitational forces only pull objects together, they do not repel objects.

400

Describe a scenario where an energy transformation would take place going from potential to kinetic.

Many answers possible.

Ex. rolling a ball down a hill, string a bow and then releasing the arrow, rolling down the top of a roller coaster, etc.

500

A roller coaster goes 1 m/s for 30 seconds up the fill, 50 m/s down the hill for 3 seconds, 30 m/s for 2 seconds around the turn, and finished off going 40m/s for 5 seconds. 

What is the average speed?

3.025 m/s

(units must be included to receive points)