How would you describe the motion of a person swinging?

When someone swings, they move forward and back as well as up and down in a repeated pattern on motion. Over time, the swings become shorter and the swing eventually stops.

If a book is pushed across the floor but doesn’t bump into anything, what makes it stop moving?

The force of friction slows down a book sliding across the floor. It slows it down so much that it comes to a stop!

If someone goes bungee jumping from a bridge, they first fall down, and then what happens?

When someone goes bungee jumping from a bridge, they fall down, then they move back up. Then they fall down again and back up again. The pattern keeps repeating. They continue to move up and down but in smaller and smaller amounts until they come to a stop.

If two identical boxes were pushed with the same amount of force, one on the sidewalk and one on an ice skating rink, which would move further? Why?

The box pushed on the ice would move further because the ice is more slippery than the cement. In more scientific terms, the force of friction between the box and the ice is less than the force of friction between the box and the cement.

Explain how the motion of a jump rope creates a predictable pattern.

When Izzy jumps rope, he knows when to jump because the rope moves up, over, down and around him in a repeating pattern.

If a ball is thrown straight up into the air, what do you predict its pattern of motion to be? Why?

We can predict that a ball thrown straight up will fall straight down again because we have likely done it before and noticed a pattern that happens every time.

Explain the relationship between string length and motion for pendulums.

The longer the string length, the slower a pendulum swings. The shorter the string length, the faster a pendulum swings.

If the length of the strings for all the pendulums in Zoe and Izzy’s model were the same, would they still create the same kinds of patterns we see?

No. The difference we see in Izzy's and Zoe's pendulums is because the strings are different lengths. If the length of the pendulum strings were the same, it is predicted that they would all swing with the same pattern of motion.

Friction is the force that resists motion.

How does rubbing two sticks together cause a fire to start?

The force of friction between the sticks creates heat. When the flammable wood gets hot enough, a fire can start.

Why does one car move down the ramp faster than the other even though they are the same and released at the same time?

One side of the ramp is rougher than the other. The rougher side of the ramp causes more friction, which slows things down.

Why is increasing friction a good thing when it comes to car tires?

Although we want cars to be able to move quickly and smoothly down a road, we also want cars to be safe and not to slide off the road! Tire treads are carefully engineered to grip the road so the car can steer and turn safely. With tires, friction is a good thing.

What are some examples of very fast motions? What about extremely slow motions?

Fast motion could include the flapping of a bee's wings, a cheetah running, an airplane flying or a speaker vibrating. Some really slow motions could be a plant growing, a glacier sliding or a snail moving. No matter how slow motion is, it's still motion!

Patterns of Motion & Friction

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What you will learn from this videoWhat you will learn

A pattern of motion is the repeated process of an object moving.
Patterns of motion can be used to make predictions.
When one surface rubs against another we get friction.
Friction slows things down.

Discussion Questions
- Before Video
  How would you describe the motion of a person swinging?ANSWER
  - When someone swings, they move forward and back as well as up and down in a repeated pattern on motion. Over time, the swings become shorter and the swing eventually stops.
  If a book is pushed across the floor but doesn’t bump into anything, what makes it stop moving?ANSWER
  - The force of friction slows down a book sliding across the floor. It slows it down so much that it comes to a stop!
  If someone goes bungee jumping from a bridge, they first fall down, and then what happens?ANSWER
  - When someone goes bungee jumping from a bridge, they fall down, then they move back up. Then they fall down again and back up again. The pattern keeps repeating. They continue to move up and down but in smaller and smaller amounts until they come to a stop.
  If two identical boxes were pushed with the same amount of force, one on the sidewalk and one on an ice skating rink, which would move further? Why?ANSWER
  - The box pushed on the ice would move further because the ice is more slippery than the cement. In more scientific terms, the force of friction between the box and the ice is less than the force of friction between the box and the cement.
- After Video
  Explain how the motion of a jump rope creates a predictable pattern.ANSWER
  - When Izzy jumps rope, he knows when to jump because the rope moves up, over, down and around him in a repeating pattern.
  If a ball is thrown straight up into the air, what do you predict its pattern of motion to be? Why?ANSWER
  - We can predict that a ball thrown straight up will fall straight down again because we have likely done it before and noticed a pattern that happens every time.
  Explain the relationship between string length and motion for pendulums.ANSWER
  - The longer the string length, the slower a pendulum swings. The shorter the string length, the faster a pendulum swings.
  If the length of the strings for all the pendulums in Zoe and Izzy’s model were the same, would they still create the same kinds of patterns we see?ANSWER
  - No. The difference we see in Izzy's and Zoe's pendulums is because the strings are different lengths. If the length of the pendulum strings were the same, it is predicted that they would all swing with the same pattern of motion.
  What is friction?ANSWER
  - Friction is the force that resists motion.
  How does rubbing two sticks together cause a fire to start?ANSWER
  - The force of friction between the sticks creates heat. When the flammable wood gets hot enough, a fire can start.
  Why does one car move down the ramp faster than the other even though they are the same and released at the same time?ANSWER
  - One side of the ramp is rougher than the other. The rougher side of the ramp causes more friction, which slows things down.
  Why is increasing friction a good thing when it comes to car tires?ANSWER
  - Although we want cars to be able to move quickly and smoothly down a road, we also want cars to be safe and not to slide off the road! Tire treads are carefully engineered to grip the road so the car can steer and turn safely. With tires, friction is a good thing.
  What are some examples of very fast motions? What about extremely slow motions?ANSWER
  - Fast motion could include the flapping of a bee's wings, a cheetah running, an airplane flying or a speaker vibrating. Some really slow motions could be a plant growing, a glacier sliding or a snail moving. No matter how slow motion is, it's still motion!
Vocabulary
- Pendulum DEFINE
- Motion DEFINE
- Pattern DEFINE
- Pattern of Motion DEFINE
- Outcome DEFINE
- Friction DEFINE
- Sandpaper DEFINE
Reading Material
DIY Activity Guide
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Lesson Plan
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Assessment
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