Phy 213 Quiz 2 5 points each Sept. 10, 2004

Draw A + B and A -B for each pair of vectors in problems 1 & 2.

Remember, the vectors on this page are real vectors, meaning you can redraw them elsewhere, but you cannot change their direction or magnitude. Make certain you make it absolutely clear to me what you mean by A + B and A - B .

1.

2.

3. Find Ax and Ay

4. Find the component of acceleration down the plane.

5. Draw the x vs t , v vs t, and a vs t curves for the ball’s motion until it rolls off the right edge of the track.

6. Draw a motion diagram of an object that has negative velocity and positive acceleration.

7. Mike falls out of a tree and lands on a trampoline. The trampoline sags 2 feet before launching Mike back into the air. At the very bottom, where the sag is the greatest, is Mike’s acceleration upward, downward, or zero? Use tools you’ve learned in these first chapters to give a convincing explanation of your answer.

Problems 8 - 10.

A 200 kg weather rocket is loaded with 100 kg of fuel and fired straight up. It accelerates at 30 m/s² for 20 seconds before running out of fuel.

8. What is it’s maximum speed?

9. At what instant after liftoff does it reach it’s maximum altitude? (Use 10 m/s² for the acceleration of gravity.)

10. Draw a velocity vs time graph for this rocket from liftoff until it hits the ground.

11. Using this v vs t graph, determine the rocket’s maximum altitude.