Physics 213 Test 1 9 Points Each Sept. 16, 2005

(One point absolutely FREE!)

Draw a motion diagram for an object that has : (don’t forget your frame of reference.)

1 Positive velocity and negative acceleration.

2. Negative velocity and positive acceleration.

3. Martha is riding in a hot air balloon, rising at a constant 5 m/s. George watches nervously from the ground. At 30 m according to her altimeter, she releases a bouquet of flowers for George to catch. How long does it take the flowers to reach George?

Below is the motion diagrams for two different objects C and D. Clock readings are indicated in the boxes.

4. Which is travelling fastest to begin with? ___________________

5. Which travels the greatest distance ?___________________

6. At which clock readings(instants) do they occupy the same location at the same time?________________

7. Is there any time interval over which they have the same average velocity? ___________________

8. What is the launching speed of an object shot straight up if it only took 2 seconds to reach its maximum height?

a. 10 m/s

b. 20 m/s

c. 30 m/s

d. 40 m/s

9. A particle moves along the x axis according to the equation x = 2 + 3t - t² . Find its position, velocity, and acceleration at t = 3 s .

10. A miner pulls a wagon of supplies to the top of a hill where he lives by hanging from a rope attached to the wagon. As the cart moves at increasing speed up the hill, the miner moves with increasing speed downward. Draw a motion diagram for the miner to determine the direction acceleration, then draw a free body diagram for the miner , then state which is largest, T or the miner’s weight ?

11. While exploring a cave, a spelunker starts from the entrance and moves the following distances. She goes 75 m north , then 250 m east, then 125 m at an angle of 37 ° north of east, and finally, 150 m south. Find her resultant displacement from the cave entrance. (Means find the sum of the given vectors.)