Force and Motion
Learning Target for the week: I can demonstrate and calculate how unbalanced forces change the speed or direction of an object’s motion
Energy: The ability to do work Energy: The ability to do work. Energy Transformation: any process of transforming one form of energy to another. Fossil fuels, solar radiation, or nuclear fuels can be converted into other energy such as electricity or heat.
Examples of energy transformation Turning on a flashlight ___________to____________ Turning on the T.V. ___________to____________&_____________ Wood burning in a fireplace
Chemical Energy: (food) energy produced by the food we eat Electrical Energy: form of energy that consists of a flow of electric charges through a conductor Thermal (heat) Energy: total kinetic energy contained in all the particles of a substance
Mechanical Energy: energy an object has because of its motion or position Other types of energy: light, sound, nuclear 2 Types 1. Potential Energy: stored energy an object has because of its position or shape 2. Kinetic Energy: energy an object or particle has because it is moving.
Simple Machines
Machine: a device that makes work easier by providing some trade-off between the force applied and the distance over which the force is applied
Lever: long rigid bar that rests on and pivots around a support Lever: long rigid bar that rests on and pivots around a support -Fulcrum: a point around which a lever turns -Effort Arm: the distance between the effort force and the fulcrum. -Resistance Arm: the distance between the resistance force and the fulcrum
Pulley: simple machine consisting of one or more wheels with a rope wrapped around them; Ex: miniblinds, flag pole Inclined Plane-reduces effort required to lift an object to a required height; Ex: handicap ramp
Wedge- 2 inclined planes joined back to back, used to split things; Ex: Axe Screw- inclined plane wrapped around a shaft or cylinder; Ex: bolt, spiral staircase
Motion of Objects
Mass: amount of matter in something measured in grams Motion: a change of the position of an object with respect to time
Equilibrium: when an object is motionless or is in motion at a constant velocity Balanced Force: occurs when an object’s motion does not change Unbalanced Force: occurs when the object’s motion changes.
Unbalanced force
20 N 30 N
Inertia: the resistance that an object has to a change in its motion Inertia: the resistance that an object has to a change in its motion. Force: a push or a pull on an object that causes a change in motion in the same direction
What is work? In science, the word work has a different meaning than you may be familiar with. Work- using a force to move an object a distance (when both the force and the motion of the object are in the same direction.) Force Motion
Work or Not? (Man is now carrying the box walking) Force Motion
What’s work? A scientist delivers a speech to an audience of his peers. A body builder lifts 350 pounds above his head. A mother carries her baby from room to room. A father pushes a baby in a carriage. A woman carries a 20 kg grocery bag to her car?
What’s work? A scientist delivers a speech to an audience of his peers. No A body builder lifts 350 pounds above his head. Yes A mother carries her baby from room to room. No A father pushes a baby in a carriage. Yes A woman carries a 20 km grocery bag to her car? No
Gravity: the force that causes objects to fall to the ground Weight: the force of gravity on an object