Unit 6 PS Standard PS 5
Drill Panther Copy down the Speeds of Animals MAKE A BAR GRAPH WITH THESE ANIMALS AND THEIR SPEEDS ON IT Animal Name on X axis Pig 11 mph Mouse 8 mph Six-lined race runner 18 mph Elephant 25 mph Moose 35 mph Lion 50 mph BAR GRAPH
Panther Drill Copy this equation: This how to figure out your speed in miles per hour 75 ft X 1 mile X 3600 sec your 5280 ft 1 hr
Your SPEED Speed = Distance divided by time For us today: ft/sec
Unit 6 Motion Motion: movement of an object from a fixed point. Fixed point is called the reference point (this is the starting line)
Distance Distancehow far something has moved. IE How far you drive in your car. It is only a number or amount. For instance LCHS is exactly 61.3 miles from my door to the parking lot. This is distance.
Displacement Displacement: is a distance and a direction. For example to get to the deer stand in the woods I had to walk 1500 yards North west from the road. Total or Final Displacement: change in position from the starting point. LOOK AT EXAMPLE ON THE NEXT SLIDE
Total displacement You travel: 6 miles east then 3 miles west A 6 miles E 3 miles W Total displacement (distance from where you started) = 6 miles – 3 miles = 3 miles. You am now 3 miles from your house.
Panther Drill What is the difference between speed and velocity?
Speed Speed: the distance traveled per unit of time. Speed (s) = distance (d)/time (t) s=d/t meters/sec Different speeds Cruise control on a empty road= constant speed Bumper to bumper traffic = changing speed, your speed is fast, then slower, then faster, then slower ect
Speed and Velocity Speed: we already know is the distance traveled in a given unit of time. Measured for science in meters per second. Can also be mph Velocity: speed with direction22 m/sec SE IE: You have to walk 2.8 mph NW from the road into the woods to the deer stand.
You are here Speed = 22 mph Speed = 22 mph Velocity = 22 mph NorthWest Velocity = 22 mph North East Who cares? You should. The red case means your butt could be toast!!! Hurricane coming right at us!!!!!! The purple case velocity means surfs up dude!!! Hurricane Fran 1996
Different speeds Constant Speed:when speed is unchanged. like cruise control in the car. Changing speed: speed is not constant or consistent. Like stop and go traffic. Average Speed:used when speed is changing, = s (avg) = Total Distance Traveled Total time spent traveling
Different speeds 2 Instantaneous Speed: Speed at any given time, only true at that instant it is observed. Instantaneous Speed Ferrari Enzo 0-60 time 3.3 secs. The speed at any time over that 3.3 seconds would be different.
Exit Explain the difference between speed and velocity.
Panther Drill If the formula for speed is s=d/t, write down how to find distance and how to find time, using the same equations. t = d/s d = sxd
Vid Clip VIDEO
Acceleration Acceleration: (a)the rate of change in velocity per unit of time Original or Initial Velocity= 20 m/sec Final velocity = 80 m/sec Time = 2 sec Acceleration = Velocity(final) - Velocity(original) time 80m/s – 20m/s a = 2 sec 60m/s / 2 sec a = 30 m/sec
A car traveling at 60 mph accelerates to 90 mph in 3 seconds. What is the car’s acceleration? Velocity(final) - Velocity(original) = Acceleration time 90 mph - 60 mph = 3 seconds 30 mph = 3 seconds = 10 mph/second
Acceleration Units The Unit for Acceleration in science is meters per second per second or m/s2 a = V final – V Initial m/s time s
Panther Drill If you are traveling at 4 m/sec and then speed up to 12 m/s in a period of 5 seconds. What is your acceleration
Panther Drill Velocity in m/s Seconds Use the graph to find out what is the acceleration between 3 seconds and 7 seconds Extra Credit: What is the slope of the line?
PD Answer Acceleration (a) = Vf – Vi t time = 7 sec – 3 sec = 4sec 14 – 6 = 8/4 = 2 m/s2 4 Vf = 14 m/s Vi = 6 m/s
Extra Credit Slope: m= (y1-y2) (X1-X2) 3 – 7 = 6-14 -4/-8 m = 2
??QUESTION?? Is the acceleration changing when you look at the graph? At what kind of rate, changing or constant? What do you see when you compare the slope with the acceleration? They are = Slope of the line = the acceleration!!!! Yes Constant
Example Joval and Justice pull up to each other at a stop light. They decide to race. The 2 cars accelerate as a traffic light turns green. In 5 seconds, Joval (car 1) goes 0-40km/hr and Justice (car 2) goes 0-50 km/hr. Which car accelerates the fastest?
You do car #2 What is its acceleration?
Panther Drill Define the following: • Constant acceleration • Changing acceleration • Positive acceleration • Negative Acceleration
Positive and Negative Acceleration Positive acceleration: speeding up Negative acceleration: slowing down Velocity is still in the same direction Velocity Acceleration Velocity Acceleration
Graphing Positive acceleration Negative acceleration
The area in red is where constant velocity occurs. Here there is 0 acceleration
Changing Acceleration In changing acceleration the graph is not a straight line with a constant slope. Changing acceleration is speeding up or slowing down.
Work Lets check it: Vi = 22 Vf = 22 t = 7 (10-3 sec) 22-22 = 0/7 = 0m/s2 7
Graphing Draw a sketch of positive, negative, constant, and zero acceleration on graph paper. Label each sketch. Make sure you title the sketches and tell me what each axis measures.. Divide the graph paper in into quarters. Put each graph in a separate ¼ of the paper.
Exit Assignment Circle the area where there is positive, negative, and 0 acceleration.
Monday Students will construct time-distance graphs PS 5.6 Represent the linear motion of objects on distance-time graphs.
Panther Drill In your own words describe Distance Displacement Speed Velocity
PRACTICEOn your graph paper graph the following data Compare the speed of the 2 objects on a graph