at home plate at 1st base at 2nd base at 3rd base back at home distance displacement

Transcription

1 You might need a calculator: The typical baseball diamond is a square 90 ft long on each side. Suppose a player hits a homerun and makes one complete trip from home plate, around the bases, and back to home plate. Complete the table by finding the player's distance and displacement as he rounds the bases. Include the proper units. (Hint: It is 127 feet from second base to home plate.) at home plate at 1st base at 2nd base at 3rd base back at home distance displacement

2 Moving Man distance (position) velocity (speed) time time

3 Quick Quiz!! What is the speed of a rocket that travels 9000 meters in seconds? After an impact involving a non functioning satellite, a paint chip leaves the surface of the satellite at a speed of 96 m/s. After 17 seconds, how far has the chip landed? How long will your trip take (in hours) if you travel 350 km at an average speed of 80 km/hr? A meteoroid changed velocity from 1.0 km/s to 1.8 km/s in 0.03 seconds. What is the acceleration of the meteoroid? In a summer storm, the wind is blowing with a velocity of 8 m/s north. Suddenly in 3 seconds,the wind s velocity is 23 m/s north. What is the wind s acceleration? A driver starts his parked car and within 5 seconds reaches a speed of 60 km/h, as he travels east. What is his acceleration?

4 Procedure: Each of you will measure your own acceleration over a 20 m run. You will run 20 m from the start line and accelerate to as fast as you can go. At the 20m line, you will stop. At 5 meter intervals your time will be recorded by the timers. On the data table, record your times under the distance you traveled. From this data you will be able to calculate your velocity at each point. Distance (m) 0 meters 5 meters 10 meters 15 meters 20 meters Time (s) Velocity (m/s)

5 Calculations: Show your work for the following. 1. Calculate your acceleration from the 0m to the 10m point. Are you accelerating or decelerating over this distance? Initial Velocity = Velocity at 0 meters. Final Velocity = Velocity at 10 meters. Use time at 10 meters. 2. Calculate your acceleration from the 10m to 20m point. Are you accelerating or decelerating over this distance? Initial Velocity = Velocity at 10 meters. Final Velocity = Velocity at 20 meters. Use time from 10 meters to 20 meters (hint, you need to subtract to find the time you ran from 10m to 20 m). Graph: Set up a graph on your own paper. Place distance on the Y axis and Time on the X axis. THEN, make a second graph with velocity on the Y axis and time on the x axis. Be sure to follow all rules of graphing. Questions: 1. Did you see an upward curve on your graph? If so, what does that tell you about your acceleration? On your graph, did you see the line flatten out to horizontal? What does that tell you about your acceleration?

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7 does not require that objects touch each other

8 Whenever there is a net force acting on an object, the object accelerates in the direction of the net force. balanced unbalanced

9 If the forces are in the same direction, add the forces together to get the net force.

10 If the forces are in opposite directions, subtract to get the net force.

11 The airplane is moving with a force of 800 N. However, there are two forces moving in opposite directions on the airplane. Just add these two forces: 40 N + 60 N = 100 N Subtract to get the net force: 800 N 100 N = 700 N The net force is 700 N. The airplane will move with a force of 700 N as a result of air friction and wind.

12 A brother is pulling a toy from his sister with a force of 6 N. The sister is pulling back with a force of 8 N. Who gets the toy? What is the net force? Draw an image and use arrows to represent the scenario.

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14 Force is measured in newtons (N)

15 An object with a mass of 300 kg is observed to accelerate at the rate of 4 m/s 2. Calculate the force required to produce this acceleration.

16 A boy pushes on a box of mass 36 kg and it moves at an acceleration of 7.2m/s 2. With what force does the boy push on the box?

17 A person with a mass of 75 kg is accelerated to 3 m/s 2.How much force was applied to him?