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Physical science: Unit one

Physical science: Unit one. motion. Warm up 08/12/2013. Bell ringer 08/13/2013. 1. In order to determine the speed of an object, what measurements must be made? In order to determine the velocity of an object, what measurements must be made? A. distance, time, and direction

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Physical science: Unit one

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  1. Physical science: Unit one motion

  2. Warm up 08/12/2013

  3. Bell ringer 08/13/2013 1. In order to determine the speed of an object, what measurements must be made? In order to determine the velocity of an object, what measurements must be made? A. distance, time, and direction B. distance and mass C. time, distance, and volume D. distance and time 2. If a squirrel runs 30 meters to the left and then turns around and runs 60 meters to the right, what is the squirrels total distance? What is the squirrels total displacement?

  4. Distance vs. displacement • Distance is how far something has traveled. • Displacement is how far out of place something is; it is the object’s overall change in position.

  5. Distance & Displacement • What is the displacement of the cross-country team if they begin at the school, run 10 miles and finish back at the school? • What is the distance and the displacement of the race car drivers in the Indy 500?

  6. Work It out: Practice • A whale swims due east for a distance of 6.9km, turns around and goes due west for 1.8km, and finally turns around again and heads 3.7km due east. What is the total distance traveled by the whale? What is the displacement of the whale? • An RV travels 45 km east and stays the night at a KOA. The next day it travels for 3 hours to the north, traveling 110 km. What is the displacement over the two days for the RV?

  7. Speed & velocity • Speed=distance/time • Remember triangle method • Velocity-the rate at which an object changes its position. • *It is speed (distance/time) with a direction.

  8. Speed & velocity • If a car travels 400m in 20 seconds how fast is it going? • If you move 50 meters in 10 seconds, what is your speed? • You arrive in my class 45 seconds after leaving math which is 90 meters away. How fast did you travel?

  9. Speed & velocity • Polar bears are extremely good swimmers.  If a polar bear is swimming with an average of 2.6 m/s, how far will it have traveled after 120 seconds? • Tree sloths are the slowest moving mammals.  On average, their velocity is 0.743 m/s.  How long does it take a tree sloth moving at this velocity to travel 22.3 m? • A plane travels 500 miles east and lands in Arizona. Then the plane travels another 500 miles east and lands in California. The entire trip was completed in 5 hours. What is the average velocity of the plane?

  10. What makes a good graph • Motion of an object over a period of time can be shown on a distance-time graph. • TIME is plotted along the HORIZONTAL axis, which is the x-axis. • DISTANCE is plotted along the LONGITUDINAL axis, which is the y-axis.

  11. *horizontal=zero slope=zero speed Distance-time graph *the steeper the slope the faster the speed

  12. Graphing You may work with a partner. Keep voice levels down, if you get too loud, you will return to your seats and work alone. On your graph paper… • Label the x axis (HORIZONTAL) as Time (seconds) and the Y axis (LONGITUDINAL) as Distance (meters). • Label X axis, start labeling time at zero and increase intervals by 5 seconds each (5, 10, 15…50) • On the Y axis, start labeling distance at zero and increase intervals by 2 meters each (2, 4, 6…40) • You will use the same time data for all the lines…plot the data..you should have three difference lines. • Color Code the distance 1 in one color. Distance 2 in another, and distance 3 in another color.

  13. Graphing data

  14. Analyze datawrite on back of graph paper • 1. Who had the fastest speed and explain why you think so? • 2. Which of the three had a constant speed? • 3. What happened to Dane during the time intervals of 25 to 35 seconds? • 4. Calculate the average speed of each. *Average speed is total distance (add up all the distances in a person’s column) divided by total time (add up all the times in a person’s column). • Example: Kherington’s distance and time 2+4+6+8+10+12+14+16+18+20=110 5+10+15+20+25=75 110/75=1.46 • 5. Make a summary statement about what the slope of the line tells you about the speed.

  15. Bell ringer 08/14/2013 • A helicopter is moving past some cloudsat a velocity of 5 km/hr north relative tothe clouds. The clouds are moving pastthe ground at a velocity of 3.5 km/hrnorth. How fast is the helicopter goingpast the ground? A 2.5 km/hr B 3.5 km/hr C 5 km/hr D 8.5 km/hr • If a shark is swimming with an average of 6.4 m/s, how far will it have traveled after 360 seconds?

  16. review Speed Velocity

  17. Acceleration • The rate that you can change your speed/velocity is acceleration. • Speeding up is a positive acceleration • Slowing down is a negative acceleration • Acceleration = Final velocity – Initial velocity Time • Average Acceleration = (Final Acceleration – Initial Acceleration) Time

  18. Acceleration • A lizard accelerates from 2 m/s to 10 m/s in 4 seconds. What is the lizard’s average acceleration? • A runner covers the last straight stretch of a race in 4 s. During that time, he speeds up from 5 m/s to 9 m/s. What is the runner’s acceleration in this part of the race? • A car advertisement states that a certain car can accelerate from rest to 70 km/h in 7 seconds. Find the car’s average acceleration.

  19. Lab…Things to know before lab • Hypothesis is an idea or explanation that you then test through study and experimentation. • Independent variable is the variable that is varied or manipulated. (HINT: What are you changing????) • Dependent variable is the response that is measured. • If a response requires you to put your units (cm, m, km,….) and you do not put them, IT IS WRONG!!!!

  20. Amendments to LAB • Page 3, under ACCELERATION MINI-LAB, UNDER INVESTIGATION MARK OUT “measure out another meter from end of ramp, and mark out every 50cm using a piece of tape on the ground”.Page 3, under ACCELERATION MINI-LAB #4, mark out have all three timers, YOU WILL ONLY HAVE ONE TIMER. • Page 3, under ACCELERATION MINI-LAB #5, mark out and100cm, you will only go to 50cm. • Page 4, under Questions /Conclusion #3, mark out 100cm and write 50cm.

  21. Lab Time • Clear everything off of your desk, except textbooks • Need only pencil and a piece of paper • Bags go under the desks or at the back of the room, OUT OF THE WAY • Working groups of 4 to 5, NO MORE

  22. Review for quiz • In order to determine the speed of an object, what measurements must be made? In order to determine the velocity of an object, what measurements must be made? A. distance, time, and direction B. distance and mass C. time, distance, and volumeD. distance and time • If a squirrel runs 30 meters to the left and then turns around and runs 60 meters to the right, what is the squirrels total distance? What is the squirrels total displacement?

  23. REVIEW FOR QUIZ • What is a reference point? • Explain the difference between displacement and distance. • What formula does the triangle method coincide with? • Polar bears are extremely good swimmers.  If a polar bear is swimming with an average of 2.6 m/s, how far will it have traveled after 120 seconds? • If you move 50 meters in 10 seconds, what is your speed?

  24. Review for quiz • Describe a distance-time graph • How do we determine acceleration? • Bristan accelerates from 5 m/s to 10 m/s in 5 seconds. What is her average acceleration?

  25. BELL RINGER 08/15/2013 • If a projectile goes from 100 m/s to 1230m/s in 180 seconds what is it’s acceleration? What is it’s change in velocity? • A car is traveling at 50 m/s and suddenly slows to 15m/s in 5 seconds. What is the acceleration?

  26. BELL RINGER 08/16/2013 • What is the definition of displacement? • Give one example of a reference point in the classroom? At your house?

  27. SRI Testing • 1. Log in as you normally would • 2. Turn off the sound on the computer • 3. Click on Desk tools from the Desktop • 4. Click on READ 180 Student Icon • 5. Click on the SRI icon on the lower left hand side of the screen • 6. LOG IN WITH YOUR ID – it is USERNAME AND PASSWORD • 7. Choose 1, 2, or 3 kinds of books you would like to read, then click NEXT • 8. Complete the Pre-Test • 9. After completing the Pre-Test, continue with the Assessment • 10. After you have finished, a screen will appear let me know, I will come over once I see that screen and tell you, you can LOG OFF.

  28. 8/16/2013 Agenda • Finish lab if you have not finished • WRITE ON YOUR OWN PAPER, WRITE QUESTION AND ANSWER for Self-Check Section Reviews • Section 1 Self Check 1-7, page 46 • Section 2 Self Check 1-7 page 51 • ACCELERATION , SPEED, and VELOCITY problems, for #2 after “ in seconds...” put 5 seconds

  29. Bell Ringer: Monday, 8/19/2013 • If Steve throws the football 60 meters in 10 seconds, what is the speed of the football? • -Take out a sheet of paper for notes…

  30. What is force? • Force is a push or pull. It is described by its strength and the direction in which it acts. • Force is measured in Newton's (N). • Force is represented by an arrow. The arrow points in the direction of the force and the length of the arrow tells you the strength of the force.

  31. Forces The combination of all forces acting upon an object is called the net force.

  32. UNBalanced forces Unbalanced forces acting on an object result in a net force and cause a change in the object’s motion or direction.

  33. BALANCED FORCES Equal forces acting on an object in opposite directions are called balanced forces. There is no net force and therefore the object’s motion nor direction are changed.

  34. Vector Diagrams

  35. Problems to Try on Your Own…

  36. Bell Ringer: Tuesday, 08/20/2013 • Two tugboats are moving a barge. One tugboat pulls to the right with a force of 3000N and the other pulls to the left with a force of 12000N. Draw the vector diagram and give the net force. • Four people are pulling on a box with theforces shown below. If there are no otherforces on the box, in what direction will itmove?A toward Diane B toward BillC toward the bottom D toward the right side

  37. An airplane has a weight of 150,000N and a lift of 45,000N. An airplane has a thrusting force of 200,000N and a drag force of 25,000N. An airplane has a weight of 100,000N and a lift of 175,000N. An airplane has a thrusting force of 100,000N and a drag force of 200,000N. An airplane has a weight of 75,000N and a lift of 205,000N. An airplane has a thrusting force of 80,000N and a drag force of 175,000N. An airplane has a weight of 25,000N and a lift of 65,000N. An airplane has a thrusting force of 65,000N and a drag 60,000N. An airplane has a weight of 52,000N and a lift of 61,000N. An airplane has a thrusting force of 154,000N and drag of 452,000N. -Remember you must state draw the vector diagram -Give the combined force (net force of the airplane -State whether the forces are balanced or unbalanced -State what will happen to the airplane.

  38. Newton’s first law of motion • A.K.A. The law of inertia • An object at rest will stay at rest, and an object in motion will stay in motion, unless it is acted upon by an unbalanced force. • Inertia is the tendency of an object to resist a change in motion. • The more mass an object has, then the greater the inertia.

  39. Everyday examples of newton’s first law…. • car suddenly stops and you strain against the seat belt • when riding a horse, the horse suddenly stops and you fly over its head • the difficulty of pushing a dead car

  40. Newton’s second law of motion Acceleration depends on the object’s mass and on the net force acting on the object. Acceleration is measured in meters per second squared. (m/s2) Acceleration (m/s2) = net force (N) ÷ mass (kg) So, what could we do to increase or decrease our acceleration?

  41. Everyday examples of newton’s second law… • hitting a baseball, the harder the hit, the faster the ball goes • The positioning of football players - massive players on the line with lighter (faster to accelerate) players in the backfield • a loaded versus an unloaded truck

  42. Newton’s third law of motion If one object exerts a force on another object, then the second object exerts a force of equal strength in an opposite direction on the first object. Every action has an equal and opposite reaction.

  43. Everyday examples of newton’s third law

  44. Everyday examples of newton’s third law… • two cars hit head on • astronauts in space • pool or billiards

  45. Newton’s laws • It takes less force to move a DVD than a DVD player. • A soccer ball will not move until a player kicks it. More force=more acceleration. • If air is let out of a balloon quickly, air pushes down & balloon goes up. • It takes less force to push a bike than a motorcycle. • Feet push down on the floor and the floor pushes up as you walk across. • 12 lb bowling ball goes faster down the lane than a 15 lb bowling ball. • Push a large box & a small box with the same force, the small box will go faster.

  46. Newton’s laws • It takes less force to move a DVD than a DVD player. Newton’s 2nd Law • A soccer ball will not move until a player kicks it. Newton’s 1st Law • More force=more acceleration. Newton’s 2nd Law • If air is let out of a balloon quickly, air pushes down & balloon goes up. Newton’s 3rd Law • It takes less force to push a bike than a motorcycle. Newton’s 3rd Law • Feet push down on the floor and the floor pushes up as you walk across. Newton’s 1st Law • 12 lb bowling ball goes faster down the lane than a 15 lb bowling ball. Newton’s 2nd Law • Push a large box & a small box with the same force, the small box will go faster. Newton’s 2nd Law

  47. NewtoN’s 3 Flaps • Supplies needed: piece of white paper, scissors, markers/crayons, or a pencil • 1. Fold paper hamburger style • 2. Cut three flaps • 3. Outermost flaps should be labeled (Newton’s 1st of Motion, Newton’s Second Law of Motion, Newton’s 3rd Law of Motion) • 4. Inward flap should contain the scientific or technical definition. • 5. Innermost flap should contain a short or easy definition. • 6. The back should contain 2 everyday examples (can be drawn or explained.

  48. Friction and gravity • The force that two surfaces exert on one another when they rub against each other is called friction. • The strength of the force of friction depends upon two things: how hard the surfaces push together and the types of surfaces involved. • Smoother surfaces tend to have less friction. While rougher surfaces tend to have more friction.

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