{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Final-solutions

# Final-solutions - PHYSICS 221 FINAL EXAM SOLUTIONS Section...

This preview shows pages 1–4. Sign up to view the full content.

24 lb 16 lb 8.0 f 2.0 ft 12.0 m 15.0 m PHYSICS 221 FINAL EXAM SOLUTIONS December 12, 2011 Section 1 - Dr. Yost Problem 1: [12pt] A ball is thrown horizontally from the roof of a 12.0-m-tall building and lands 15.0 m from the base. (a) [5pt] What was the ball’s initial speed? (b) [7pt] What was the ball’s final velocity (magnitude and angle with respect to horizontal)? Problem 2: [12pt] A cat is sitting 2.0 feet from the end of an 8.0-foot long board that is suspended at the ends by two ropes of negligible mass. The center of mass of the board is at its midpoint. The tension in the rope at the left is 24 lb, while the tension in the rope at the right is 16 lb. The parts of this problem can be answered together. If you can’t answer them individually, show as many specific relations as you can for partial credit.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 (a) [6pt] How much does the cat weigh (in pounds)? Balancing torques about the center of the board gives (taking counterclockwise torques about the center to be positive) (b) [6pt] How much does the board weigh (in pounds)? Balancing the vertical forces gives Problem 3: [12pt] A 1250 kg satellite is launched from earth, entering space with a speed of 8.50 km/s. Assume that it is steered into a circular orbit with no change in energy. (a) [6pt] What is the total mechanical energy of the satellite? Assume it would have zero total energy if it were at rest infinitely far from the earth, and see the front page for useful constants. Its initial kinetic energy just after launch is (with 1 GJ = 10 9 J) Its initial potential energy is The total mechanical energy is Alternative solution: , so and
3 (b) [6pt] What is the radius of the satellite’s circular orbit?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 7

Final-solutions - PHYSICS 221 FINAL EXAM SOLUTIONS Section...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online