378W.

1958X.

19.58

105Z

1. For each of (a), (b), and (c) below, single grammatically correct sentence containing the words indicated that makes scientific sense. You may use conjunctions; a list of definitions,

(a) , orbit, gravity, separation, period.

(b) , Kepler, angular, area, third.

2 an explanation, based on a scientific theory, of why objects fall if they are held up above the ground and then let go. Explain why it is scientific. Then write down a non-scientific explanation of the same phenomenon, and explain why it is non-scientific. Then write down a pseudoscientific explanation of the same phenomenon, and explain why it is pseudoscientific.

3. a mathematical calculation about the rotational displacement of an object with an angular acceleration ofYradians per second squared and initial angular velocity ofXradians per second after 0.025 second.

4. computes the parallel and normal forces exerted on an object ofZkilograms sliding down a 60-degree inclined plane with a coefficient of friction of 0.8. Draw a sketch of the system in the question, labeling the key quantities.

5. Three children are playing on a skating rink. Allie slides southward and runs into Billie and imparts a force ofYnewtons. Callie slides westward, also runs into Billie, and imparts a force ofZnewtons. Billie's mass isYkilograms. Draw a diagram of this system, labeling any vectors or quantities that are significant; then calculate Billie's velocity two seconds after the collisions.

6. In a fire, a person of massZkilograms jumps out of a second story window. Calculate (a) the person's weight; (b) the kinetic energy of the person upon reaching the ground if they stand on the windowsill when they jump; (c) the person's kinetic energy upon reaching the ground if they hang by their outstretched arms from the windowsill and then drop down to the ground; and (d) how the person can land 2 meters away from the wall.

7. You need to lift a person with a mass ofZkilograms who is laying in bed into a wheelchair next to the bed. If the distance from your hand to your elbow isYcentimeters and the distance between your shoulder and lower back isZcentimeters, how much force will your lower back muscles experience if you lift by leaning over the wheelchair? Sketch a diagram to help explain your reasoning, and show your calculations.

8. Referring to Question 7 above, how much force will your lower back muscles experience if you lift by sliding the person in a seated position into the wheelchair while you maintain as upright a position as possible? Refer to the diagram from Question 2 above or draw a new one.

9. Referring to Questions 7 and 8 above, is it likely you will injure your lower back muscles in either lifting activity? Explain quantitatively why or why not, citing all references you use. If injury is likely, then write down two physics-based ways of lifting this patient that avoid injury.