Week 3 Shirley's Blog

 

Lab: This week we discuss the home work assignment article, Motivating three-Dimensional learning from student's questions, also talked about what affects a rider's speed down a slide, which is the big problem in this week. 

-Rider weight

-Slide material

-Rider clothing

-Initial push

-Slide slope

-Slide length

-Turns on slide

-Weather (snow, wet) 

-Using a wat, etc

-Waterslide 

 

We use different materials to time the how many times we need slide to the different positions( 20m,15m,10m,5m)

Then we got the claim is smoother the material, the faster the rider will go. Change of the material , the change of speed rider will go.

Lecture：We talked about why will the speed of a rider on tall slide be higher than on a shorter slide? It will be increased. Move very quickly at the beginning, and very slow at the end.

Acceleration=change in velocity/time

Why does height matter?

-Riders acceleration as they slide down a slide

-The higher the slide, the more time a rider has to speed up

The force lens on motion

Defining forces

-A force is a push or a pull

-Objects accelerate because of force

-Acceleration is can be speeding up, slowing down, or changing direction

-A force is required for objects speed up, slow down, or change direction

What is friction? 

-Friction is a force that sliding across a surface

-Magnitude depends upon:

    1. Types of surfaces (stickiness, roughness)

    2. How hard the surfaces are pushed together.

Pressbook: The Force lens on Motion

Force:  a force is a push or a pull, and always have a magnitude (size) and a direction. They are best represented using vectors, or arrows.

Newton's First Law

Objects at rest remain at rest, while objects in motion stay in motion unless acted on by an unbalanced external force.

Things not move because: A force does not just magically appear by itself on an object; there needs to be another object acting on it in some way.

Friction: A force that holds back the motion of a sliding object

Kinetic friction & static friction

Inertia affects objects move, heavier objects have more inertia.

Newton's Second Law

The greater the mass of an object, the more force it will take to accelerate the object.

F=ma

Newton's Third Law

If Object A pushes on Object B, then Object B simultaneously pushes back on Object A with the same size force in the opposite direction.

Gravity, magnets, and electrostatic forces (static electricity) are all forces acting between objects at a distance.

NGSS: Performance Expectations: 

Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.

DCI: 

Kindergarden 

-Pushes and pulls can have different strengths and directions.

-Pushing or pulling on an object can change the speed or direction of its motion and can start or stop it. (K-PS2-1),(K-PS2-2)

Third Grade 

Each force acts on one particular object and has both strength and a direction. An object at rest typically has multiple forces acting on it, but they add to give zero net force on the object. 

Middle School

-All positions of objects and the directions of forces and motions must be described in an arbitrarily chosen reference frame and arbitrarily chosen units of size. In order to share information with other people, these choices must also be shared. (MS-PS2-2)

-Objects in contact exert forces on each other. (3-PS2-1)