Slow projectile - shoot a monkey

Fast projectile - shoot a monkey

Motion

Objectives

You will be able to explain:› Motion› Distance› Speed› Velocity

Motion

Motion- when an objects distance from another object is changing

› Reference point- place used as a comparison to determine motion

Distance

Distance- always measured using the metric system

Kilometers, meters, centimeters, millimeters

Speed

Speed- the distance an object travels per unit time

Speed=Distance/Time

Speed Lab

Speed= M/Second

1 meter per second = 2.23693629 miles per hour

Student Number

Distance Time Speedm/s

Speed mph

1234..

10 m10 m10 m10 m..

Avg. Avg.

Baseball Pitch

The pitchers mound is 60’ 6” from home plate. This is equal to 18.39 M.

If it takes a pitch 1 second to get to home plate, how fast was the pitch?

Remember 1 meter per second = 2.23693629 miles per hour

Answer=

Speed

Speedsters

Speed In Science and Sports

Ndamukong Suh

Velocity

Velocity is speed in a direction. V=D/T

Velocity

Velocity is a vector quantity that refers to "the rate at which an object changes its position." Imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. While this might result in a frenzy of activity, it would result in a zero velocity. Because the person always returns to the original position, the motion would never result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity. If a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. Every step must go into moving that person further from where he or she started. For certain, the person should never change directions and begin to return to the starting position.

Review1. Ben Roethlisberger can throw a football 60

yards in 4 seconds. How many ft/ second is that?

2. If there are 5,280 ft per mile, how fast is Big Bens pass in mph?

3. A bullet from a sniper rifle can travel 5,760 ft/ second. How many miles/ hr is that? How far would it travel in 10 seconds? 3927mph

4. If a train travels 275 miles in in 5 hours, what is its average speed? What is its velocity?

5. If I throw a boomerang out at a40 mph and it returns at a speed of 40 mph, what is its average speed? What was its velocity?

MotionNewton's Three Laws

Acceleration

A=(End V - Start V)/time

Force

Newtons Second Law- Force

Force- the product of an objects acceleration and mass Measured in Newtons

Force = Mass x Acceleration You can rearrange the formula to find

acceleration or mass if needed Acceleration = Force/Mass

Force in sports

Force in sports video

Force Problems

A 52 kg water skier is being pulled by a speedboat. The force causes them to accelerate at 2 m/s. Calculate the net force that causes this acceleration.

What is the net force of a 1000 kg elevator accelerating at 2 m/s?

What net force is needed to accelerate a 55 kg cart at 15 m/s?

Force Continued

How can I increase the force of a football players tackle?

How can I increase the force of a paintball to increase its range?

Friction

Friction- the force that two substances exert as they rub past each other

Lets burn something old school style!!! Stick fire

Friction

There are three types of friction› Sliding friction-when solid surfaces slide

over one another

› Rolling friction-when an object rolls over another object

› Fluid friction-when an object moves through a liquid or gas

Friction

Phonebook Friction Meter Stick friction demo

› Take a meter stick and slide your hands towards oneanother and notice where they meet.

› Now start one 50% closer to the middle of the stick and notice where they meet.

› Why?

Friction Lab

Do you think that a quarter, dime, or nickel will fall more quickly?› Place a quarter, dime, and nickel at the

edge of your desk.› Put a ruler behind them so they can be

pushed off evenly.› Push all three over the edge at the same

time.

What was the result?

Bell Ringer

List an example of the three types of friction.

How does friction affect force?

What is often a byproduct of friction?

Gravity

Gravity- the force of two objects pulling towards each other

9.8 m/s2

So each second an object falls its velocity increases by this rate until terminal velocity is reached.

Air resistance has an effect on gravity Killer Penny

Gravity

Bullet Drop vs. Shot Notice the math these guys do. Proof

that math is cool.

Lets look at the book pg. 58

Terminal Velocity

An object can only fall so fast. At some point it reaches what is known as TERMINAL VELOCITY

When air resistance = Gravity

For a human this is at about 53m/ S2 or 120mph

Gravity Questions

Calculate your velocity if you jumped from an airplane and fell for 11 seconds.

Gravity= 9.8 m/S2

Calculate your velocity if you jump from a swing at 10 ft.

Conversion-

Motion Graphing

Objectives› Use Proper Scale› Determine X & Y axis labels› Determine speed, acceleration, and

velocity by using graphs

Newton's Third Law

If an object exerts force on another object, the second object exerts the same force in the opposite direction.

So what does that mean?› It means if you and a friend stand on an icy

surface and one of you pushes the other you both move equal distances

Momentum

Momentum- is the quantity of motion

› Momentum = Mass X Velocity

Momentum Problems

Which has more momentum:› A 3 kg sledgehammer swung at 1.5 m/s or

a 4 kg sledgehammer swung at .9 m/s?

› A 90 kg hockey player skating at 10 ft/s or a 75 kg player skating at 17 ft/s

› A 142 gram baseball going 95 mph or a 190 gram softball traveling 74 mph?

Forces in fluids

Pressure- Pascal- Fluid- Pascal’s Principle- Hydraulic system- Buoyant force- Archimedes Principle- Density- Bernoulli’s principle-

Building a Glider

You and your team will have one week to build a glider from Styrofoam. The goal will be the longest flight from my rescue window. You will receive one full class period the day before the flight and 10 min. of each class period up until the flight. The tools for this assignment will be :

Foam Glue Paper clips Bernoulli’s Principle

Pressure

Pressure = Force/Area

› Measured in Pascal's (Pa) 1N/M2 =1PaOr

N/cm2 for smaller units

Snow Shoes and Surface area

Book pg. 78

Air Pressure

The air around us exerts pressure on our body.› Why don't we get crushed?

Air pressure at sea level =10.13N/cm2 More often we use a more common

measure of air pressure (mmHg) › 1 mm Hg = 133.322368 Pascal's› 760 mm Hg is the standard air pressure at

sea level. This is known as Barometric pressure

Pressure at Elevation

Air pressure is less at elevation. So, water boils espier because the molecules are freed more easily.

› What affect does this have on cooking times?

› Soda Can› 55 Gallon Drum

Pressure at Depth

As you go deeper the pressure increases.

Pg. 83 Water Bottle

Buoyancy

Buoyant force- force that works against gravity to keep things afloat

Sinking- when gravity has more force than buoyancy

Floating when buoyancy equals or is greater than gravity

Archimedes Principle- the buoyant force of an object is equal to the weight of water that object displaces

Density

Density= mass/volume

Density determines weather or not something will float

Review of density

If I have a block that is ten cm long by 20 cm wide by 30 cm deep, and its mass is 1000 g, what is its density?

What is the density of a liquid that fills a 100 ml beaker and weighs 100 grams? What liquid would this most likely be?

If a wooden block has a density of 2 g/cm3 will it float or sink?

Bernoulli’s Principle

The faster a fluid moves the less pressure it exerts.

This is why a plain can fly.