TWO DIMENSIONAL KINEMATICS

For this exercise you are to fire the cannon under a variety of circumstances to reinforce your understanding of the parameters that govern the total range and pathway of the projectile.

You should record velocity, angle, range, max height for each shot. You can entire in comments if you like in the last column.

In each case you should be able to predict the max height and the total range from the lecture notes and material located here.

The cursor read out is in meters and gives both the X and Y position. The grid on the background has a size of 20x20 meters. The X and Y positions should be measured with respect to the black horizontal line. Note the Y postion of that line is Y =45 so remember to subtract 45 meters from all Y measurements.

Exercises:

1. Set the angle to 45 degrees and the velocity to 20 m/s. You should be able to figure out the range now. Try and do that and enter that value into the spread sheet. Shoot the cannon to verify your answer.

2. Now change the velocity to 30 m/s. You should be able to calculate the range directly from what it was for 20 m/s. Try it.

3. Change the angle to 90 degrees now. Make a predition for the range (in this case it will be the maximum height). Shoot the cannon to determine what the ratio of the horizontal range you determined in 2 above to the vertical height you just achieved. Can you think of a reason why this ratio is what it is?

4. Change the angle to 30 degrees. Set the velocity to 40 m/s. Calculate the range and shoot the cannon to test your prediction.

5. If you now change the gravity to -4.8 what do you expect for the total range? Test your answer

6. Reset gravity to -9.8. Set the velocity to 50 and the angle to 60 degrees. Record the maximum height as well as the x-position of the maximum height. Change the angle to 30 degrees and verify that the maximum height is reduced by a factor of 3. Can you state why this is a factor of 3 lower? Did the x-position at maximum height change?

7. What do you expect the ratio of the maximum heights to be for the angles of 20 and 40 degrees respectively.? Test your expectation.

8. On some unknown planet you notice a band of enemy:
   

   grungehogs approaching. Looking around your notice there is a non-adjustable cannon. Using your trusty grungehog-range-meter scope you determine that the grungehogs are located at a distance of 360 meters from you. KILL THE GRUNGEHOGS