620 likes | 846 Views
energy. the ability to do work. Energy cannot be created or destroyed, but it can be changed. potential energy. stored energy because of an object’s position. kinetic energy. energy due to an object’s motion. highest potential energy. gaining potential energy. kinetic energy.
E N D
energy the ability to do work
Energy cannot be created or destroyed, but it can be changed.
potential energy stored energy because of an object’s position kinetic energy energy due to an object’s motion
highest potential energy gaining potential energy kinetic energy
mechanical energy the ability to make something move
motion the change in an object’s position
Distance how far an object travels amount of space between 2 points
Distance ÷ Time = Speed If you travel 2 miles in 5 minutes: 2 miles ÷ 5 minutes .4 5 2 .0 .4 mi/minute 2 0 0
Distance ÷ Time = Speed To change .4 mi/minute to mi/hr: .4 x60 24 mi/hr 24 . 0
100 meters in 5 seconds 20 20 m/sec 100 5 100 0
50 yards in 6 seconds 8 .3 8.3 yd/sec 6 50 48 2 0 18 2
instantaneous speed speed of an object at any one moment average speed average speed an object travels during an entire trip
Speed x Time = Distance 100 km/h for 3 hours 100 300 kilometers x 3 300
velocity distance an object moves over a given amount of time in a certain direction
Dad is driving west at 105 km/h. west 105 km/h velocity
Jim runs 10 km/h. 10 km/h not velocity
velocity scientific common used interchangeably with speed, leaving out direction as a factor distance an object moves over a given amount of time in a certain direction
acceleration scientific common to go faster a change in velocity (change in speed and/or direction)
deceleration scientific common to slow down a negative change in velocity (change opposite of acceleration)
Lindy maintains the 150 mi/h speed as she travels north on the track. velocity
Rodney comes alongside and matches Lindy’s speed. Lindy increases her speed to get to the finish line before Rodney. acceleration
force a push or pull applied to an object in order to change its velocity
friction a force that keeps objects from moving against other objects
1st Law of Motion An object tends to stay at the same velocity unless another force causes it to change.
inertia resistance to a change in motion
gravity the pull of one object on another object
2nd Law of Motion Force is equal to an object’s mass and the acceleration of the object. mass x acceleration = force
Principles the greater the mass of the object, the greater the force needed to move it the greater the force, the greater the acceleration the greater the acceleration, the greater the force on the object
mass x acceleration = force ma = f force ÷ mass = acceleration f/m = a force ÷ acceleration = mass f/a = m
3rd Law of Motion When one object exerts a force on another object, the second object reacts by exerting an equal force back on the first object. Law of action and reaction
https://edvance360.com/v7/c_video_player.php?c=10&video=2657
work a force acting on something and moving it a distance
force x distance = work If an object does not move, the distance is zero. any number x 0= Therefore, no work is done. 0
force x distance = work newtons × meters = joules
force x distance = work You use 4 newtons of force to lift a box 3 meters: 4 newtons x 3 meters 12 joules
force x distance = work You use 6 newtons of force to lift a box 2 meters: 6 newtons x 2 meters 12 joules The same amount of work is done!
machine any object that makes work easier
simple machines lever pulley wheel and axle inclined plane wedge screw
Simple Machines increase speed increase force change the direction of the force
Machines can’t reduce the amount of work; they just make work easier. force x distance = work
lever any bar that turns on a point seesaw wheelbarrow broom
effort force force applied to simple machine resistance force force that works against the effort
First Class Lever effort resistance fulcrum
First-class lever resistance effort fulcrum
Second-class lever resistance effort fulcrum
Third-class lever effort resistance fulcrum
pulley grooved wheel with a chain or rope wrapped in the groove
fixed pulley attached to something that does not move