5 M S 2 Q The example essay topic

Exploring Motion and Forces Calculating Speed: Section 1 q The SI unit for distance is meters. q The SI unit for speed is meters per second. q What is the SI unit for time is seconds. Calculating Speed: Section 2 q When solving for speed, you are looking for meters per second (velocity). q Your speed is 5 meters per second. 100/20 = 5 q You skate faster. Calculating Speed: Section 3 q When solving for speed, you are looking for meters per second (velocity). q Her average speed was 9.37 meters per second. 200/21.34 = 9.37 Calculating Speed: Section 4 q When solving for time, you are looking to end up with distance over velocity. q If a lightning bolt strikes the ground 1 km away from you, it will take. 30 seconds for the sound to reach you.

100/330 = . 30 Calculating Speed: Section 5 q If the 60th floor is 219 m above the first floor, it would take the elevator 21.9 seconds to go from the 1st floor to the 60th floor. 219/10 = 21.9 Calculating Speed: Section 6 q It would take 5 hours to finish the race if the river was 130 km and you were traveling downstream. 10 km / hr is added to your speed of 16 km / hr because you are moving downstream.

130/26 = 5 q If you were traveling upstream, it would take 21.6 hours. 10 km / hr is subtracted from your speed of 16 km / hr because you are moving upstream. 130/6 = 21.6 Velocity and Speed: Section 1 q They have the same velocities. q They have the same speeds. q There is no difference between speed and velocity. Calculating Acceleration: Section 1 q The car's average acceleration is 3 m /'s 2. q The average acceleration is positive because the car is gaining speed. Calculating Acceleration: Section 2 q The roller coaster's acceleration is 7.3 m /'s 2. Calculating Acceleration: Section 3 q The swimmer's acceleration is.

01 m /'s 2 during this interval. Calculating Acceleration: Section 4 q The acceleration of the roller coaster is -5 m /'s 2. q The average acceleration is negative because the roller coaster loses speed. Putting the Knowledge to Work: Hypothesis Questions You can measure a runner's speed by calculating distance traveled over time. q Running twice as far would take twice as much time if the runner is moving at a constant speed. Putting the Knowledge to Work: Data and Observations Putting the Knowledge to Work: Analysis Distance (meters) 0-5 5-10 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 Robbie's Time (short). 95 1.11.

60.67. 68 m /'s 2 6.38 m /'s 2 -1.60 m /'s 2 26.16 m /'s 2 Duran's Time (short). 42 1.58. 9.63. 69 1.7. 24.27 1.23.

78.53. 81.50. 39 Velocity 7.25 m /'s 2.94 m /'s 20.83 m /'s 16.52 m /'s 4.07 m / 's. 4 1.22.

72.41. 96.46. In the cases of both runners, to run twice the distance, it took less than twice as long. However, if they had run at a constant speed the entire time, it would have taken twice as long to run twice as far. 2. a.) See graph. b.) The interval of greatest speed was different for each runner. c.) Robbie holds the record for fastest 5 m interval at 20.93 m / 's. d.) Both runners seem to quickly gain speed and hit a high point, then either remain at that speed or slacken a bit before gaining speed just before the end. e.) It took them about 2.75 seconds to reach full speed. 3. Distance Average Speed Robbie Short 8.2 m /'s Duran Short 7.54 m /'s Robbie Long 14.22 m /'s Duran Long 7.4 m /'s Going Further Ruth's average speed is 2 m / 's.

Sean's average speed is. 92 m / 's. Ruth's instantaneous speed 11 second after she starts is 2 m / 's. Sean's instantaneous speed 11 second after he starts is 1 m / 's. Sean stops briefly. Sean and Ruth run at the same speed during the 3-4 second interval.