Read this to learn about the importance of triangles in truss bridges.
http://www.education.com/science-fair/article/effect-triangle-size-strength-truss/
PBS
http://www.pbs.org/wgbh/buildingbig/bridge/basics.html
Compression vs. Tension Article
http://science.howstuffworks.com/engineering/civil/bridge2.htm
Compression vs. Tension Video
Search: DSN Animation: What is tension/compression in YouTUbe if link does not work.
http://youtu.be/c-V_8_qmJbE
Different Types of Bridges Breaking
Search: Bridge Project 3/11 Matthew in YouTube if the link doesn't work
http://youtu.be/HSHVAJz7M1Y
Search: Emma and Taylor's Popsicle Stick Bridge Holds 168 lbs in YouTube if the link doesn't work
http://youtu.be/qwaW1GXa7Zw
Triangle
Search:
http://youtu.be/QheSSHUbPeE
http://www.education.com/science-fair/article/effect-triangle-size-strength-truss/
PBS
http://www.pbs.org/wgbh/buildingbig/bridge/basics.html
Compression vs. Tension Article
http://science.howstuffworks.com/engineering/civil/bridge2.htm
Compression vs. Tension Video
Search: DSN Animation: What is tension/compression in YouTUbe if link does not work.
http://youtu.be/c-V_8_qmJbE
Different Types of Bridges Breaking
Search: Bridge Project 3/11 Matthew in YouTube if the link doesn't work
http://youtu.be/HSHVAJz7M1Y
Search: Emma and Taylor's Popsicle Stick Bridge Holds 168 lbs in YouTube if the link doesn't work
http://youtu.be/qwaW1GXa7Zw
Triangle
Search:
http://youtu.be/QheSSHUbPeE
Chapter 11 - Exploring Forces
Study Guide
Name: Core:
Lesson 1 -Forces in Motion
distance - the length between two places
position - this describes somethings location
motion- a change in an object’s position compared to fixed objects around it
speed- how fast an object’s position changes with time at any given moment
velocity - a description of a moving object’s speed and direction
acceleration- a change in the velocity of an object over time
force - a push or pull exerted by one object on another, possibly causing a change in motion
friction - a force that opposes the motion of an object in contact with a surface
Newton’s first law of motion - an object at rest tends to stay at rest and an object in a straight line at a constant speed tends to keep moving that way UNTIL acted upon by another force.
Motion
Velocity and Acceleration
Force
Lesson 2 - Changes in Motion
Newton’s second law of motion - an object’s acceleration depends on the object’s mass and the amount of net force applied to it
Newton’s third law of motion - for every action there is an equal and opposite reaction
Newton’s law of universal gravitation - the planets, the stars, and the Sun all exert gravitational forces.
motion - a change in an object’s position compared to fixed objects around it
momentum - the mass of an object multiplied by its velocity
weightlessness - the state of being without weight
Acceleration
Force and mass affect an object’s acceleration.
A gravitational force pulls objects towards Earth’s center.
Momentum
Conservation of Momentum
Mass, Weight and Gravity
Weightlessness
Lesson 3 - Work and Energy
work - force applied to an object times the distance the object moves in the direction of the force
energy - the ability to do work
potential energy - stored energy
kinetic energy - energy of motion
thermal energy - the temperature of a substance or the movement of kinetic heat energy from one substance to another
power - the amount of work done per unit of time
law of conservation of energy - energy may change form but it cannot be created or destroyed
Work
Energy Forms
*The law of conservation of energy states that energy cannot be created or destroyed.
FORMS OF ENERGY
FORM
EXAMPLE OF SOURCE
chemical
food
electrical
a generator, a battery
light
the Sun, an electric lamp
mechanical
moving parts in a machine
sound
vibrations of a stereo speaker
thermal
hot water in a radiator
nuclear
the Sun, radioactive material
Energy Transformation
Power
Lesson 4 - How Machines Work
simple machine - a device that makes it easier to do work; it has few, if any, moving parts
mechanical advantage - the number of times a simple machine multiplies an effort force
lever - a simple machine consisting of a rigid bar and a pivot point
fulcrum - the pivot point in a lever
wheel and axle - a simple machine that consists of a wheel that applies an effort force and a smaller axle that produces an output force
pulley - a grooved wheel that turns by the action of a rope in the groove
inclined plane - a straight, slanted surface that can multiply an effort force
screw - a simple machine made of an inclined plane wrapped around a central bar that can multiply an effort force
wedge - an inclined plane that changes the direction of the applied force
compound machine - a device that is a combination of of two or more simple machines
efficiency - the ratio between the work done by a machine and the work put into it; for example - if you hardly put any effort into it and it does a lot of work for you, then the machine is very efficient.
Types of Simple Machines
Types of Levers
Compound Machines
Study Guide
Name: Core:
Lesson 1 -Forces in Motion
distance - the length between two places
position - this describes somethings location
motion- a change in an object’s position compared to fixed objects around it
speed- how fast an object’s position changes with time at any given moment
velocity - a description of a moving object’s speed and direction
acceleration- a change in the velocity of an object over time
force - a push or pull exerted by one object on another, possibly causing a change in motion
friction - a force that opposes the motion of an object in contact with a surface
Newton’s first law of motion - an object at rest tends to stay at rest and an object in a straight line at a constant speed tends to keep moving that way UNTIL acted upon by another force.
Motion
- Motion can be described by position, direction and speed.
- Forces affect motion. So if you apply a force such as a push or pull, the object might move.
- Using distance and direction can help you identify the position of something.
- Apparent motion is when you ride in a car and objects appear to move backward.
Velocity and Acceleration
- Speed is how fast something is going
- The average speed of something is the total distance divided by the total time.
- Velocity is speed and direction the object is moving.
- Acceleration is a change in velocity.
Force
- Continuous - always happening, doesn’t stop
- gravity/weight, thrust, lift
- Momentary - occurs for brief periods of time
- baseball bat hits ball,
- Some Examples of Forces:
- buoyancy
- magnetic force
- gravitational force
- friction
- Types of Friction
- static - the force between two solid objects which keeps the objects from moving
- sliding - the force that opposes the sliding of an object over a surface
- rolling - the force that opposes the motion of a wheel turning along a surface
Lesson 2 - Changes in Motion
Newton’s second law of motion - an object’s acceleration depends on the object’s mass and the amount of net force applied to it
Newton’s third law of motion - for every action there is an equal and opposite reaction
Newton’s law of universal gravitation - the planets, the stars, and the Sun all exert gravitational forces.
motion - a change in an object’s position compared to fixed objects around it
momentum - the mass of an object multiplied by its velocity
weightlessness - the state of being without weight
Acceleration
Force and mass affect an object’s acceleration.
- Greater mass deceases acceleration.
- Greater for increases acceleration.
- acceleration = net force/mass (a = F/m)
A gravitational force pulls objects towards Earth’s center.
Momentum
- Momentum measures the mass and the speed of the object
- If two balls are moving at the same speed, the ball with greater mass will be harder to stop.
Conservation of Momentum
- total momentum does not change when objects collide
Mass, Weight and Gravity
- The distance between objects affects the force of gravity. As the distance between objects increases, the force of gravity decreases.
Weightlessness
- Skydivers and astronauts experience a feeling of weightlessness, however gravity still pulls them toward the center of Earth’s mass.
- The planets, stars and the Sun all exert the force of gravity.
- True weightlessness only exists where objects are too far away from any other object to experience the pull of gravity.
Lesson 3 - Work and Energy
work - force applied to an object times the distance the object moves in the direction of the force
energy - the ability to do work
potential energy - stored energy
kinetic energy - energy of motion
thermal energy - the temperature of a substance or the movement of kinetic heat energy from one substance to another
power - the amount of work done per unit of time
law of conservation of energy - energy may change form but it cannot be created or destroyed
Work
- Work is what is necessary for a force to move an object.
- You can calculate work by multiplying the force by the distance the object moved.
- Work = force x distance, J = N x m
- Work is measured in joules (J). Also called Newton meters. (Nm)
Energy Forms
- The ability to do work is energy.
- A moving object has kinetic energy.
- Potential energy is energy that is stored.
- Thermal energy is the heat energy in an object.
*The law of conservation of energy states that energy cannot be created or destroyed.
FORMS OF ENERGY
FORM
EXAMPLE OF SOURCE
chemical
food
electrical
a generator, a battery
light
the Sun, an electric lamp
mechanical
moving parts in a machine
sound
vibrations of a stereo speaker
thermal
hot water in a radiator
nuclear
the Sun, radioactive material
Energy Transformation
- Energy can move from one form to another.
- Examples:
- Light energy enters a plant, the plant turns it into chemical energy.
- Solar panels change light energy into electrical energy.
- Chemical energy (gas) goes into the car and gets changed to mechanical energy.
- A stove burner turns electrical energy to heat energy.
- A fan changes electrical energy to mechanical energy.
- A squid changes chemical energy to light energy.
- A light bulb changes electrical energy to light energy.
Power
- Power is the amount of work done divided by time.
- Power is expressed in joules per second, also known as a watt.
- Power = J/s = W
Lesson 4 - How Machines Work
simple machine - a device that makes it easier to do work; it has few, if any, moving parts
mechanical advantage - the number of times a simple machine multiplies an effort force
lever - a simple machine consisting of a rigid bar and a pivot point
fulcrum - the pivot point in a lever
wheel and axle - a simple machine that consists of a wheel that applies an effort force and a smaller axle that produces an output force
pulley - a grooved wheel that turns by the action of a rope in the groove
inclined plane - a straight, slanted surface that can multiply an effort force
screw - a simple machine made of an inclined plane wrapped around a central bar that can multiply an effort force
wedge - an inclined plane that changes the direction of the applied force
compound machine - a device that is a combination of of two or more simple machines
efficiency - the ratio between the work done by a machine and the work put into it; for example - if you hardly put any effort into it and it does a lot of work for you, then the machine is very efficient.
Types of Simple Machines
- Lever
- Wheel and Axle
- Pulley
- Fixed pulley
- Movable pulley
- Inclined Plane
- Wedge
- Screw
Types of Levers
- First Class
- Fulcrum is between effort force and output force
- Examples: teeter-totter, pliers, scissors, balance
- Second Class
- Output force is between effort force and fulcrum
- Example: wheelbarrow, bottle opener, paper cutter
- Third Class
- Effort force is between output force and fulcrum
- Example: fishing rod, broom, tweezers
Compound Machines
- A compound machine is a combination of two or more simple machines.
- Efficiency is the ratio of the work done by a machine to the work that was put into it.
- A machine that you don’t have to put much energy into, but it does a lot of work is very efficient.