1. What is Physics?

2. Physics is… The science of the study of energy – Involved on the atomic level (like what we just covered in Semester 1) – Involved in moving large objects (like cars, people…) – And waves

3. Who was Newton? Considered to be the father of physics Came up with some basic laws Great mathematician

4. Who was Einstein? Another great scientist and mathematician Famous equation: E = mc 2

5. Objectives Determine relative motion between objects Recognize displacement of an object Relate speed to distance and time Distinguish between speed and velocity Recognize that all moving objects have momentum Solve problems involving time, distance, velocity, acceleration, and momentum

6. Objectives, cont. Interpret graphs and determine slope of a graph Know the difference between scalars and vectors and find resultant vectors Define and use acceleration Know and use Newton’s Laws of motion that include: mass, inertia, weight, and force

7. Other terms: Centripetal force, gravity, potential energy, kinetic energy Types of forces: weak, strong, gravitational, and electromagnetic

8. Motion Physicists study motion of large objects first because they are easy to see There is some math involved so you will need your circle sheets to help you keep track and make the learning move more smoothly…

9. The formulas of motion Speed = distance time Momentum = Mass x velocity Write these formulae on your triangle Sheet. V = d t  = m v d V. t  m v

10. To compare speeds of various objects – Humans 5.0 km/h – Horse 68 km/h – Eagle 184 km/h – Race car 346 km/h – Jet 925 km/h

11. Distance-Time Values for a Racing Car Time (s)Distance (m) 00 196 2192 3288 4384

12. Graph of distance versus time 600 500 400 300 200 100 0 02.557.510 Dist. (m)Time (s) jet car eagle horse walker

13. Terms Speed – distance traveled divided by the time interval during which the motion occurred Speed – distance traveled divided by the time interval during which the motion occurred Velocity – speed in a specific direction Velocity – speed in a specific direction Samples: Samples: 90 m/s is a speed 90 m/s is a speed 90 m/s north is a velocity 90 m/s north is a velocity

14. Speed is a scalar. It has only a number with units (called a magnitude). Other samples of scalars: mass (5.00 kg) volume (395 g/cm 3 ) Velocity is a vector. It has magnitude and direction Other samples of vectors: weight (70.0 n down) acceleration (35.0 m/s 2 East)

15. Vectors are shown with arrows 5 m/s E 5 m/s E 3 m/s W 3 m/s W Vectors “add” if they are in the same direction 2 m/s E +1 m/s E = 3 m/s E + = + = Vectors “subtract” if they are in opposite directions. + = + = 2 m/s E - 1 m/s W = 1 m/s E

16. Find the velocity in meters per second of a swimmer who swims exactly 110 m toward the shore in 72 s. V = d = 110m = 1.5 m toward the shore t 72s s d V. t

17. Find the distance traveled by a horse that is moving at 68 km/h if it runs for 45 minutes. Answer in meters. d = vt 45 min =.75 h d = 68km.75 h = 51 km h d = 51 km1000m km Ans: 51,000 m d V. t

18. Metric system - distance km hm dam m dm cm mm From where you start, count the number places that you move to get to the desired unit. Move decimal point that number and in that direction. We start at km and go three spaces to right to m. Move decimal 3 to the right… so 51 becomes 51000

19. Velocity assignment See next slide Read the sample then do – Practice 1. - 4.

21. Momentum,  Greek letter “rho” The product of the mass of an object and its velocity  = m v Units:kg m s

22. Momentum problem What is the momentum of a 0.8 kg kitten running to the left at 6.5 m/s?  = m v = 0.8 kg (6.5 m/s)  = 5 kg m/s to the left

23. Anything that moves has momentum Heavy objects (trains) moving slowly have large momentum and are difficult to stop. Very small objects (bullets) moving very fast have large momentum and are difficult to stop but easy to get moving. Assignment: next slide / do practice 1abde

25. Activity on the next slide Real World Applications In groups of no more than 3, complete the assignment. Equipment: paper, ruler, calculator. Complete spreadsheet in Life Skills class.

27. 1. One cover sheet is due per group 2. Each group member is responsible for doing each of the following: a. determine how far the hikers travel by measuring distance from Ambition Lake to Blackcap Mountain. b. using legend at bottom of map, determine time to walk the distance at the rate of 5km/hr.

28. Determine altitude change c. Using the given altitudes in #1 on page 222, determine the number of meters they climb (change in altitude). d. Using the climbing rate of 600 m/ hr, determine how much time it takes to climb from the lake to the mountain.

29. e. Add the walking time and the climbing time to calculate how long (in hours) it will take the hikers to reach their destination.

30. 3. Create a spreadsheet using Excel in Life Skills class that applies Naismith’s rule. (This rule is discussed on page 222 in our book.) a. Your spreadsheet headings could include:time / distance walked time / distance climbed b. if time permits (for extra points) make a graph of 1) Distance walked vs time and 2) Distance climbed vs time I am king of the hill!