Motion Chapter 11

Motion _________ an objects change in position relative to a reference point __________ a point or object used to describe a particular location _____________ used to describe the motion of an object relative to the reference points around it Example: Stand by a chair and use it as a _________ of reference. You can tell I have motion because my position around the chair _________

Distance In order to describe _________ we need to be able to measure distance Or how far an ______ moves Distance can be measured in a _______ of units What are some? ___________ distance between starting and ending point __________ must always tell us which direction we are going

Speed Some objects move _______ than others We _________ this by finding their speed _______ how fast an object moves Speed = Distance/Time (meters/second) Speed does not take into account ________ If direction is needed then one must find velocity __________= Distance/Time (speed of an object in a particular direction)

Velocity & Direction Direction is described by using _____________-or from a particular point North ______ East West Moving in the same direction is + moving in the __________ direction is – Speed can only be + but velocity can be either ________________ may also be found by adding or subtracting velocities depending on their direction

Instantaneous Speed You could find the ________ of anything at a given point in time by measuring their distance traveled in a smaller time ________ Meaning: Instead of asking how fast did I drive on my way to work you would measure how fast you went from certain points that are closer together than home and work.

Graphing ________ can be graphed by using a _______ x Time graph __ axis is time and __ axis and distance _______ as a (x, y) point = (time, distance) The ______ of the line is the speed of the ______ The greater the ______ the higher the speed Straight lines on a graph __________ that an object is not moving

Acceleration ________ the change in velocity or direction over time Meaning: how much you speed up or slow down in a given _______ of time By changing direction you can “________” without actually changing speeds Everything on earth has _________ because it is changing direction Acceleration is + when ________up and – when slowing down

Calculating Acceleration

Graphing Acceleration _______ time graph (x axis is time y axis is distance) A _________ line on a speed vs. time graph means the speed changes by the same amount over a time ________ Acceleration is the ______ of the line

Motion & Force _______ action exerted on a object in order to change the body’s state of rest or motion _____________: Electromagnetic (friction) _________ Nuclear force

Fundamental Forces Vary in ________ and the ________ over which they act ___________ strongest of the forces Holds together protons and neutrons in the nucleus ___________ 2nd strongest found in friction Holds together atoms (+ nucleus and – outer shells) ___________ the weakest of the forces Used to keep us on the ground on earth

Contact vs. Field Forces _____________ _____________ If you push on something it moves If you catch a ball it goes from moving to a _________ A force that needs to have contact in order to _______ Do not require objects to come in contact __________ Magnetic force

Forces Forces can be balanced or ___________ To move a _________ will you push in the same direction or opposite? ________= combination of all the forces acting on an object The object will move in the _________ of the greatest force Example……

Forces ___________ do not change motion meaning they are not moving Unbalanced forces move in the _________ of the greatest force

Friction Force _________ a force that opposes motion between two surfaces that are in contact Match on a rough surface _______ Tires ________ with pavement cause a vehicle to slow down Friction can cause heat ________ friction between two surfaces that are not moving ________ friction between moving surfaces Rolling Sliding (more friction than rolling)

Friction Without _________ we would not be able to do many things we do today: Drive a car ______ Fire Friction can be lowered by using a ___________ that prevent direct contact between two services Oil, ________, grease To increase _________ surfaces can be made rough Gravel or ______ on icy roads