Motion, Forces, and simple Machines Andrew Lisbon Tuesday 5/6/2014

Motion

Motion Is Relative Motion depends on a reference point Choosing a reference point A reference point on earth’s motion

Motion is a change in Position Distance

Speed Speed- is the distance traveled divided by the time it takes to travel the distance. Average speed equation average speed (m/s)=

Velocity Changing velocity Velocity- of an object is the speed of an object and its direction of motion.

Acceleration Acceleration- is the change in velocity divided by the time needed for the change of occur.

What is a Force Forces has size and direction Force- is a push or a pull.

Combining Force Forces in the same direction Forces in the opposite direction

Balanced and Unbalanced Forces Balanced forces- if the net force is not on zero, the force on an object are unbalanced force. Unbalanced forces- the force on the dresser were unbalanced when you both pushed on the dresser.

Unbalanced Forces cause motion to change Unbalanced forces cause change in speed Unbalanced forces cause change in direction

Inertia Inertia and mass Inertia- is the tendency of an object to resist a change in its motion.

Contact Forces Friction The size and direction of friction Air resistance Contact force- the force exerted by your hands on the dresser is a contact force because your hand had to touch it. Friction- is a force that oppose the relative motion of two surface that are contact.

Non-contact Forces

Gravity Gravity depends on mass and distance Gravity- is the pull that every object always exerts on every object due to their masses.

Mass and Weight

What is a machine Simple machine- is a machine that uses only one movement to do work.

Making Work Easier Input work and output work Mechanical advantage- of s machine equals the output force divided by the input force.

The Pulley Pulley- is an object like a wheel, that has a groove with a rope or cable running through it.

The Lever The wheel and axle Lever- is a rod or plank that pivots about a fixed point called the fulcrum.

The Inclined plane The Wedge The Screw Inclined plane- is a flat, sloped surface.