Forces
Force equals what?
•Mass x Acceleration
what is..
A force that acts against motion between objects that are touching
Friction
The tendency of an object to ____ a change in motion
Resist
what is
• the force applied through a distance
•Object must move in the same direction as the force
Unit for work is a joule
work
Action-Reaction do not equal ______
balanced forces
When two forces acting on the same object are the_____ strength (magnitude/size) but acting in ______ directions, they are BALANCED FORCES
SAME
OPPOSITE
What is
•A force that pulls matter together
•Between objects that are not touching
Gravity
The higher the____ of an object , the higher its ____ is.
mass
inertia
true or false
Simple Machines do NOT reduce the amount of work. You DO NOT do LESS work with simple machines. They Make it easier
true
Finish the sentence;
•For every action (force)..........
there is an equal but opposite reaction (force)
•Will change an objects motion (speed and direction)
UNBALANCED FORCES
•The more____ an object has, the _____ its gravity
mass
stronger
–Object at rest will remain at rest
–Object in motion will continue in motion in a straight line
UNLESS _______
an unbalanced force acts upon it
_____ the mechanical advantage makes the work ______ because you need less applied force
Increasing
Easier
•They are_____ balanced forces because the forces act on _____objects
not
different
Force Diagrams DO NOT show the _______ OR _______
speed or direction the object is moving. It just shows the forces acting on the object (size & direction
_____ is the force that keeps planets from falling into the sun
______ is the force that opposes motion
gravity
friction
What happens to things in a car, if the car is going 60mph and it stops?
the objects will want to continue going 60mph
Name the 6 simple machines
1. Inclined plane
2. Screw
3. Wedge
4. Pulley
5. Lever
6. Wheel and Axle
What is the action and reaction in a balloon letting out its air?
action: air rushes out of balloon (down)
reaction: balloon goes up
•Net force is calculated by ______ in the same direction or ______in opposite directions
adding forces
subtracting forces
-----> [] <-----
10 n 10n
What is the net force?
Balanced or Unbalanced?
0 N Balanced
What happens if you are on a roller coaster and it makes a sharp turn?
your body will want to continue going straight and you will be pushed into the carts wall
A doorknob is a type of wheel and axle.
In the doorknob shown above, when the handle is rotated a distance of 49 millimeters, the spindle is rotated a distance of 7 millimeters. What is the mechanical advantage of this doorknob?
7 millimeters
What is the action and reaction in a hammer hitting a nail?
Action: Hammer hitting the nail
Reaction: Hammer coming back at you