relative motion 1 which train is moving? watch video here

Relative Motion 1

Which train is moving?

Watch video here

Relative Motion 2

Make cut out bus or train with the windows cut out, 2 or 3 cut out people, a beautiful background (forest, city, etc),

and your phone.1. Place your cut out bus on the background and place your people

on the bus. Move the people back and forth at the same speed within the bus. Keep the viewing frame of your phone locked on (moving with) the cut out people. According to what you see in your viewing frame, are the people moving?

2. Move the people and the bus back and forth while keeping your viewing screen locked on the bus and having the bus fill up your viewing screen. How are things moving?

3. Now keep your viewing frame locked on the background and slowly zoom out. How are things moving?

A blue car moves along a street with two passengers. One sits in the front passenger seat of the car and the other passenger sits in the back seat. A red car moves in the same direction and is passing the

blue car. A green car moving faster than the blue car, is directly behind the blue car. There is a sidewalk along the road the cars are

traveling and a pedestrian is standing on the sidewalk.

Relative Motion 3

Describe the movement of the front passenger in the blue car as seen by each of the following observers: 1. The person sitting in the backseat of the blue car.2. The pedestrian standing on the sidewalk as the blue car passes.3. The driver of the red car moving in the same direction and passing the blue car.4. A passenger in the green car.

A blue car moves along a street with two passengers. One sits in the front passenger seat of the car and the other passenger sits in the back seat. A red car moves in the same direction and is passing the

blue car. A green car moving faster than the blue car, is directly behind the blue car. There is a sidewalk along the road the cars are

traveling and a pedestrian is standing on the sidewalk.

Relative Motion 4

1. Imagine you are the backseat passenger in the blue car, how would you observe the other four observers? Explain.2. Imagine you are the pedestrian in the street, how would you observe the other four observers? Explain.3. Based on your answers above, explain what it means when someone says an object is “moving”.4. Consider the phrase “motion is relative”. Use your idea of what it means to move to explain the meaning of this statement.

Create your own relative motion videos.

Relative Motion 5

Velocity 6

A toy car moves 2m every 2s for 10s. What kind of a

representation is this? Create as many representations of this

as possible.

• Verbal• Picture• Index• Table• Function/Equation• Plot Graph• Motion Diagram

Smashy Smashy Car Crashy

Where will 2 cars collide?

Velocity 7

CuriosityObserve Data then Hypothesize from Data

PatternsObservation ExperiementMethod

• Materials• Timer• Meter Sticks• Sand Bags• Blue & Red Car

• Procedure• Error/Uncertainty

Results• Data

Reason a Hypothesis from Patterns in Data

Velocity 8

Represent with a…• Table• Plot Graph• Motion Diagram

SkepticismPredict to Test your Hypothesis

Predict the outcome of a Testing Experiment assuming your Hypothesis is correct.

Perform the Testing Experiment then compare the actual outcome to your prediction. Your test is an experiment and must include…

Testing ExperiementPredictMethod

• Materials• Procedure• Error/Uncertainty

Results• Data• Compare Predicted to Actual Outcome, Revise if Necessary

Velocity 9

Represent with a…• Table• Plot Graph• Motion Diagram

Represent this data

with motion diagrams,

graphs, and equations.

Predict where they will meet. How did

you predict?

Position (x) Time (t)

1m 0s

2.5m 1s

4m 2s

5.5m 3s

Position (x) Time (t)

10m 0s

8m 1s

6m 2s

4m 3s

Shiv

Megha

Velocity 10

Force & Acceleration 11

How does a ball move if it ……rolls to a stop?…is on a ramp?

…is on a ramp with an initial velocity up the ramp?

Materials: Meter sticks, balls, sand bags, books, timers

We have learned that V = Δx/Δt

What is acceleration?Use words and equations for your

answer.


How do we calculate acceleration?

How could we find Vf from this if we know all other physical

quantities?

Kinematic Equations 13

12 tt

vv

t

va if

tavv if


Vf

Vi


Create as many mathematical procedures for finding displacement as you can think of.

Derive the following kinematic equations below from three you have created.

advv if 222

2

2

1attvd i


Substitute

tvvd if )(2

1

tavv if

to get 2

2

1tatvd i

into


Multiply

tvvd if )(2

1

to get

by

advv if 222

12 tt

vv

t

va if


How do you do these activities?• You pedal a bicycle to start moving then apply the

brakes to make it stop moving.• You hit the accelerator (gas pedal) to make a car

speed up after the light turns green, then you hit the brakes to stop for the next red light.

• A spring pushes a marble to accelerate it out of your launcher.

• You push a baseball to speed it up for a throw. A friend then pushes on the ball after it enters her glove to slow it down and catch it.


Hypothesize how motion changes.

Materials (every single material MUST be used)• Mass scales• Your muscles and bodies (you lift things up and put them

down… grarghhh!!!!!)• Big ball (bowling/medicine)• Medium ball (tennis/baseball/pool ball/ cricket ball)• Small ball (marble)• Stopwatch• Meter stick

Newton’s 1st and 2nd Law 20

Make a force diagram for a… … box sitting stationary on the ground. …box being pushed on a rough surface but remaining stationary.…box being pushed along a rough floor at a constant velocity.

Force Diagrams & Newtons 1st Law 21

Hypothesize how friction operates on a subatomic scale.Materials: phet.colorado.edu ‘Friction’

Friction Force 22

Hypothesize the relationship between the friction force of the floor on your shoe and the amount of normal force exerted by the floor on your shoe.

Spring Force 23

Hypothesize the relationship between the force used to

stretch a spring and the distance it is stretched.

Hypothesize a quantitative model for the force which moves objects

in circles. Materials: ball on a string

Central Force 24

central force

Hypothesize the relationship between the quantities which determine the gravitational force between two objects.

Materials: phet.colorado.edu ‘Gravity Force Lab’

Gravitational Force 26

How do gravitational forces differ from more mundane forces such as the push of a hand or the pull of a rope?

Gravitational Force Field 27

Draw a diagram of the force exerted on objects with mass (system masses) by a massive central object (source mass).

THEN ERASE THE TEST OR SYSTEM MASSES (not the center source mass)

Gravitational Force Field 28

Dennis throws a tennis ball away from Earth with an initial velocity of 100 m/s up.Make a position vs. time graph and V vs. t graph. What is the acceleration? How high does it go (distance)? How far away is it from where it started (displacement)?

Time (s) Position (m)0 01 95.12 180.43 255.94 321.65 377.56 423.67 459.98 486.49 503.1

10 51011 507.112 494.413 471.914 439.615 397.516 345.617 283.918 212.419 131.120 40

Acceleration 29

Projectile PhysicsHypothesizeDesign an experiment to hypothesize what the

initial velocity of a marble being shot out of your launcher is.

***!!!Reminder!!!***Experiments need methods, data, assumptions and

error/uncertainty.

Analysis of the data is looking for patterns and your conclusion is your hypothesis from these patterns.

Projectiles 30

Projectile Physics

PredictNow we test our hypothesis by

predicting how far our launcher will launch if firing at a 30o angle.

Projectiles 31

Lets consider a ball being launched across a flat field where the initial and final heights of the ball are the same.

Derive an expression for the horizontal distance travelled solely in terms of the

initial velocity, acceleration due to gravity, and the angle at which it is fired.

Projectiles: Range Equation 32

***Hints!!!***1. How could we make our reference frame as easy as possible for ourselves?2. What kinematics equation could we use which requires the least assumptions

and is the most comprehensive?3. How do we link the horizontal and vertical components?4. How could we simplify?

Newton’s 3rd Law 33

Hypothesize how two things push or pull on each other.

Materials: 2 bathroom scales2 spring scales2 scooters

Jackie exerts a 9.8 N force upward on a 1 kg snowball

on Earth. Draw this situation focusing on the snowball.


Jackie exerts a 9.8 N force upward on a 1 kg snowball

on Earth. Draw this situation focusing on Jackie’s hand.


Predict to test Newton’s Laws

Materials: phet.colorado.edu ‘Forces and Motion’

Newton’s Laws 36

Make charts for… 1. Kinematic Equations which includes Math, Uses/Limitations, and Diagram.2. Newton’s Laws which includes Math, Words, and Diagram.3. Types of forces which includes Math, Words, and Diagram

Forces and Motion 37

Make a Venn diagram comparing Motion (Kinematics) and

Forces (Dynamics).

1 D Momentum 38

Consider the following:1. A softball is pitched underhand.

2. The driver of an Abrams tank hits the gas.

If they both have the same final velocity and acceleration to get to that final velocity, what is different about these two scenarios? How would the force and motion diagrams for these two compare? How could we account for this?

1 D Momentum 39

You have bowling balls, pool balls, tennis balls, and golf balls. Create

experiments to observe what happens during various collisions.

Invent a physical quantity to communicate these situations.

Keep in mind this physical quantity must combine the factors unique to motion and forces respectively.

1 D Momentum 40

Hypothesize the aspects of this new physical quantity (momentum).

Design experiments using: 1. pool ball and a golf ball

2. phet.colorado.edu ‘collision lab’Make sure to identify the

independent, dependent, controlled, and confounding variables. Include

assumptions and error.1 D Momentum 41

Summary of Momentum• P=mV units are kg(m/s)• Impulse changes momentum J=mΔV=FΔt• Momentum can be transferred from one

object to another.• Momentum is conserved if there is no impulse

(outside force exerted in a change in time) exerted on the system ΣPi + J = ΣPf

• Collisions can be described as inelastic (sticky) or elastic (bouncy)

• Momentum is described with diagrams, math(s), and bar charts

1 D Momentum 42

Create bar graphs to chronicle the following scenario.

• You have no money in your pocket, $60 in your ATM account, and a gift card with $20 on it. You withdraw $20 cash from the ATM.

• Next, you buy a lemons and a pitcher for $10 cash at Jones Grocery. (The initial state for this process is the same as the final state of the previous process.)

• After returning from the grocery store, you make lemonade and manage to sell enough to make $10.

• When you are finished selling lemonade, you spend $20 cash to put gas in your car so you can drive to Target.

• At Target, you purchase the new Super Mario Brothers game for Wii for $50. You empty out your gift card and use your ATM card to pay for the rest.

Conservation of Momentum Bar Graphs 43

Aditi and Cheryl are competing over who can make a ball stay airborne for the longest amount of time. The displacement through which Aditi accelerates the ball out of her hand is 0.2m, while Cheryl accelerates the ball out of her hand during the throw in exactly 2s. Aditi throws the ball with an initial speed of 40 m/s and Cheryl throws her ball so the total vertical path covered is 164m. When the balls hit the ground they both have an inelastic collision with the ground and an impulse of 75 kg m/s is exerted on the balls by the ground. Whose ball stays in the air for the longest amount of time?

Momentum Problem 44

We created momentum as a combination of both motion and forces together… but does momentum always make

our physics easier? Does it always work?

Create testing experiments to test the hypothesis that momentum

P=mV ΣPi + J = ΣPf

is a viable physical quantity which makes doing physics easier.

You are trying to DISPROVE this. Nothing is proven… ever… nothing… nada… zilch… goose egg.

Work 45

Suggested Materials

• Chalk and brick• String with sandbag• Wind up Toys• Whatever your creative minds can come up

with (within the bounds of reason and politeness)

Create testing experiments to test the hypothesis that

momentumP=mV

ΣPi + J = ΣPf

is a viable physical quantity which makes doing physics

easier.

Work 46

Materials: Chalk and massive object

For cases wherein momentum is no longer

a viable physical quantity to use, invent a new physical quantity to

analyze these phenomena.

Work 47

What is fundamentally different between the physical quantity you

invented and momentum?What about your new physical

quantity allows makes it easier to analyze the situations momentum

couldn’t?

Work 48

A man carries a 5kg bowling ball up a 2m ladder then walks another 5m on the roof while carrying it. How much total work is done on the bowling ball? Make sure to make both a force and motion

diagram for each part.

Work 49

What is different and similar between the everyday idea of work and how we describe it in

physics?

Work 50

Hypothesize where work goes when you do work to lift a tennis

ball. Derive a mathematical expression for the amount of

‘stored work’ whenever work is done lifting something.

Stored Work 51

Hypothesize where work goes when you do work to move an object. Derive a mathematical expression for the amount of

‘stored work’ whenever work is done to move something. Use the equation for work you discovered

and kinematic equations.Stored Work 52

Hypothesize where work goes when you do work to stretch a spring. Make a spring force vs. displacement graph. Derive a

mathematical expression for the amount of ‘stored work’ whenever

work is done stretching a spring.

Stored Work 53

Work gets stored as Energy

• Work done stretching a rubber band or compressing & stretching a spring is stored as elastic potential energy

» EPE=0.5kΔx2

• Work done lifting an object such as a ball is stored as gravitational potential energy

» GPE=magΔx

• Work done making an object move is stored as kinetic energy

» KE=0.5mV2

Energy 54

You stretch a slingshot 1m which has a spring constant of 1000N/m.

You place a 1kg ball in the slingshot. Ignore air resistance. If you release it vertically, how high

will it go? What will the final velocity of the ball be?

Energy 55

Design a virtual observation experiment to discover an

explanation of friction in terms of work and energy.

Materials: PHET Friction

Friction with Energy 56

Mayes is driving home from a full night of coming up with awesome things to do in class. My car masses 1,633 kg and is moving at 20.0 m/s. There is a red light 40m ahead of me. The coefficient of kinetic friction between the road and my car tires is 0.04. Will I run the red light or stop in time? Do it with energy, momentum, and forces.

You Choose What To Use 57

You stretch a slingshot 1m which has a spring constant of 1000N/m.

You place a 1kg ball in the slingshot. Air resistance is 2N for the entire flight. If you release it

vertically, how high will it go? What will the final velocity of the

ball be?Energy 58

You stretch a slingshot 1m which has a spring constant of 1000N/m. You place a 1kg ball in

the slingshot. Air resistance is 2N for the entire flight.

Energy 59

Analyze this situation with a bar chart assuming the system is:

1. The ball.2. The ball and Earth.3. The ball and the slingshot.4. The ball, the slingshot, and Earth.5. The ball, the slingshot, Earth, and the

surrounding air.

Design and perform virtual testing experiments to test the following hypotheses separately on Energy

Skate Park PHET:Work and Energy is Conserved

KE=1/2mV2

GPE=mgΔxI suggest you turn on and use all tools available to you in

the simulation. FRICTION MUST BE ‘ON’ WITH A COEFFICIENT OF FRICTION BETWEEN ‘NONE’ AND ‘LOTS’.

Energy 60

Energy 61

Something happened one day and it was described by Matt in the following way.

½ kx2 + Wdrag= ½mV2 + mgy

Create a scenario for what this could possibly describe with a diagram, a

bar chart, and words.

Hypothesize the maximum velocity

of a bouncy toy using only

measuring tape.Energy & Momentum 62

Hypothesize the spring constant of your springy toy

using only measuring tape and

a mass scale.Energy & Momentum 63

Hypothesize the work done in each single

wind of a wind-up toy using measuring tape

and a spring scale.Energy & Momentum 64

Energy & Momentum Conservation 65

A Newton’s cradle consists of a series of metal spheres hung in a row. One is raised then falls as a pendulum and strikes the row of other spheres. Thus, a sphere at the opposite end bounces up. It is possible for one sphere to fall on one end and have a sphere raise on the other side. Likewise, it is possible for two spheres to fall, strike the row, and two spheres bounce up at the other end. Is it possible for one sphere to strike the end and have two sphere bounce up on the other? Is it possible for two spheres to strike one end and have one bounce up on the other?

Gravitational Potential and Electric Potential Energy 66

Hypothesize how much energy is had by two charges near each other.

Hypothesize how much energy is had by two masses near each other.

Materials:•Your expression for gravitational force, electric force, and mechanical work.•Phet – Gravity Force Lab

What is similar and different about these situations? Compare with a

Venn diagram. Then, come up with a physical quantity (index) to compare the two scenarios.

A flexed muscle quickly pushes a marble with 10N of force over 1m.

A light breeze pushes a marble slowly with 10N over 1m. Power 67

What is different and similar between the everyday idea of

power and how we describe it in physics?

Power 68

Power 69

A 5kg box slides to a halt from 5m/s over a distance of 20m. What is the coefficient of kinetic friction between the ground and the box? How much work is done due to friction on the box? 62.5 J How much power is exerted on the box?

m = 5kg

V0 = 5m/s Vf = 0m/s

ΔX = 20m

You have various ramps with the same height but each have

different paths. If we roll marbles down each of these ramps and release them at the same time, predict which ramp will take the

least amount of time for the marble to travel from the top to

the bottom.

Power 70

a) You rescue a 0.05kg bird from the sidewalk and place it back in its nest, 5.2m up in a tree, in 1.0s.b) You lift a 6kg bag of Oreos 3.0m up to your tree house in 6.0s for your slumber party with your friends (you have been saving up for all the Oreos).c) You lift a 10.4kg bag of rice 2.6m to the top of the pantry for your mom in 2.3s.d) Your 70-kg sister twisted her ankle so you lift her from the foyer to the second floor 4.0m straight up in 10.0s.

Power 71

You have developed superpowers overnight. You can now stretch your arms to reach ridiculous heights. You decide to become a hero and on your way home from school, you do the following heroic acts. Determine how much power you

exert while lifting the following objects. Draw a picture of the initial and final states.

Exercise Power HouseYou’ve got the POWER!

Hypothesize the amount of power required to run up a single stair.

BE VERY VERY CAREFUL!

Power 72

Exercise Power HouseNow that we know the power

delivered by legs while climbing stairs, create a proposal for a Stairmaster which will power all the lights in a

house (ignore the kitchen).Many assumptions must be made to

do this.Power 73

Simple Machines 74

Bree and Yash are debating the best way to put bowling balls away on the lab table after an experiment. Bree says it is easier to use a ramp to roll the bowling ball back to the lab table she got it from. Yash says it is easier to

simply lift the ball and put it on the lab table.

Who is right? Design experiments to gather evidence to

validate your claim.

Simple Machines 75

Tim claims that he made a machine out of a simple pulley and a string which will reduce

the amount of work done to lift a mass to a specific height. Create

a testing experiment with a prediction to test this

hypothesis.

Simple Machines 76

Do research and design your own

simple machine which does something to improve your life!

Misconceptions 77

Misconceptions

Motion is absolute. Everyone will agree on the motion of an object.

A force is required for motion. Objects eventually stop with no forces exerted on them.

Motion is in the direction of the net force.

For every action there is an equal and opposite reaction and the sum of the 'actions' is 0.

Nothing is conserved if there is impulse/work.

A large truck collides with a compact car. The truck exerts a greater force and conveys a greater momentum to the car.

A ball is projected up by a spring and there is no air resistance. If the ball is the system no work is done, energy just transfers.

Objects move in a circle because of the tangential velocity due to the centripetal force.

Semantics of Gravity/Electricity

Concept/Skill from which you must create...

Educational Problem with rubric and solution (make it fun or funny).

Scientific Experiment to investigate something cool.

Engineering Design which will in some way make life easier.

Game 78

relative motion 1 which train is moving? watch video here

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