Motion, Speed & Velocity

Motion & Speed

Motion, Speed & VelocityMr. Hollanders Science Class

110/9/13Mr. Hollander's 8th Grade Science ClassMotion, Speed & VelocityWhat is Motion???Look aroundwhat is in motion around you?Air particles movingEarth circling the sunBlood traveling in your veinsMotion is an objects change in position relative to a reference pointMotion can be described through directions like north, south, east, west, left, up, etc.

210/9/13Mr. Hollander's 8th Grade Science ClassMotion, Speed & VelocityReference Points & MotionReference points can be nonmoving objectsEarths surfaceTreeBuildingReference points can be moving objects tooTwo cars driving at one anotherA football being thrown to a wide receiver

SpeedHow Fast or Slow Motion Happens!!!Speed is the distance traveled by an object divided by the time taken to travel that distanceIt is related to motion because it explains how fast or slow something is moving based on the reference point used to determine motion is taking placeSpeed is usually measured as meters per second (m/s)Other measures include km/h, ft/s, and mph.

Average SpeedMost of the time, objects do not travel at a constant speedExample: In a car you stop and go, obey different speed limits, trafficAverage speed allows for a calculation to take place in order to some up the general distance and time covered through motionAve. Speed = Total Distance Total TimeSpeed can be easily graphed as distance versus time

Calculating SpeedKira jogs to a store 10 miles from her apartment. It takes her 2 hours to do so. What is her average speed?An airplane traveling from Cincinnati to Baltimore travels 800 km in 2 hours. What is the airplanes average speed?Read the following problems and answer what the average speed would be for each.Michael Phelps swims 100 meters in 50 seconds. What is his average speed?

Direction Matters: Velocity & AccelerationVelocityVelocity is the speed of an object in a particular directionIt is very important that you always include a directionEx: Speed is 5 mph, but Velocity is 5 mph SouthConstant velocity takes place in a straight line, but if speed or direction change, so does velocity

AccelerationAcceleration is the rate at which velocity changes over timeAn object is said to accelerate if its speed, direction, or both change.Positive acceleration is an increase in velocityNegative acceleration is a decrease in velocity

So What is Acceleration Again?? Lets Talk About ItLook at the following situations. Did acceleration occur and why?A boy is riding a bike at 10 km/h. A minute later he is at 5 km/h.You ride your bike around the block at a constant speed of 15 km/h.You ride in a straight line at 10 km/h.

Summing It All Up!!!An object is in motion if it changes position over time in relation to a reference point.Speed is the distance traveled by an object divided by the time the object takes to travel that distanceSpeed can be represented on a graph of distance versus timeVelocity is the speed in a given directionAcceleration is the rate at which velocity changes

The End!!!

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