Please Note: All parts covered in green will not be on the test.

Physics 201 Midterm 1 Exam October 27, 2004
Please enter your last name and university ID number on front page of the answer sheets. You must fill in all the appropriate bubbles for your name, ID number, and section number. Also sign your name in the space provided at right. Before you begin the exam, fill in the ID information requested on all pages of the solution papers.
Directions: The exam consists of 13 questions - 10 multiple choice and 3 problems. Only approved calculators may be used for this exam. Palmtop or laptop computers and graphing calculators are not allowed. In solving problems, show your work and explain your reasoning. Except for multiple-choice questions, no credit will be given for an answer that does not include the necessary solution or explanation. Partial credit may be awarded for a correct method of solution, even if the answer is wrong. Please place your answer to the multiple-choice questions in the appropriate box on the answer sheet. Work only on the front of the pages of the exam booklet, and if more space is needed for your solution please direct accordingly (i.e. continued on back page). Use only the exam booklet provided.
sin= opp/hypcos = adj/hyptan = opp/adj A2 + B2 = C2
vavg = Δx / Δta = Δv / Δtv = vo + a tΔ = final - initial
vavg = (vo + v) / 2x = (vo + v) t / 2x = vo t + ½ a t2v2 = vo2 + 2 a x
Fnet = m aW = m g fk = μk FN fsmax = μs FN
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Multiple Choice Questions (4 points each): IT IS NOT NECESSARY TO SHOW YOUR WORK FOR THESE MULTIPLE CHOICE QUESTIONS.
Choose the one correct answer for each of the following questions that best answers or completes the question. Place your answer in the appropriate box on the answer sheet.
1. / Complete the following statement: The term net force most accurately describes
A) / the mass of an object
B) / the inertia of an object.
C) / the quantity that causes displacement.
D) / the quantity that keeps an object moving.
E) / the quantity that changes the velocity of an object.
2. / A particle travels along a curved path between two points P and Q as shown. The displacementof the particle does not depend on

A) / the location of P. / D) / the shortest distance between P and Q.
B) / the location of Q. / E) / the direction of Q from P.
C) / the distance traveled from P to Q.
3. / Which one of the following statements must be true if the expression is to be used?
A) / x is constant. / D) / a is constant.
B) / v is constant. / E) / Both v0 and t are constant.
C) / t is constant.
4. / A baseball is hit upward and travels along a parabolic arc before it strikes the ground. Which one of the following statements is necessarily true?
A) / The acceleration of the ball decreases as the ball moves upward.
B) / The velocity of the ball is zero m/s when the ball is at the highest point in the arc.
C) / The acceleration of the ball is zero m/s2 when the ball is at the highest point in the arc.
D) / The x-component of the velocity of the ball is the same throughout the ball's flight.
E) / The velocity of the ball is a maximum when the ball is at the highest point in the arc.
5. / Note the following situations:

In which case will the magnitude of the normal force on the block be equal to (Mg + F sin θ)?
A) / case 1 only / D) / both cases 2 and 3
B) / case 2 only / E) / cases 1, 2, and 3
C) / both cases 1 and 2
6. An object is moving along a straight line. The graph shows the object's position from the starting point as a function of time.

In which segments(s) of the graph does the object have the highest speed?
A) AB B) BC C) CD D) DE E) AB and CD
7. / Two sleds are hooked together in tandem as shown in the figure. The front sled is twice as massive as the rear sled.

The sleds are pulled along a frictionless surface by an applied force F. The tension in the rope between the sleds is T. Determine the ratio of the magnitudes of the two forces, .
A) 0.25 B) 0.33 C) 0.50 D) 0.67 E) 2.0
8. / Two vectors A and B are added together to form a vector C. The relationship between the magnitudes of the vectors is given by A + B = C. Which one of the following statements concerning these vectors is true?
A) / A and B must be displacements.
B) / A and B must have equal lengths.
C) / A and B must point in opposite directions.
D) / A and B must point in the same direction.
E) / A and B must be at right angles to each other.
9. / The net force on a moving object is suddenly reduced to zero. As a result, the object
A) / comes to stop abruptly.
B) / changes direction.
C) / continues at constant velocity.
D) / decelerates and eventually comes to stop.
E) / changes velocity in an unknown way. continues at constant velocity.
10. Two 5-N boxes are attached to opposite ends of a spring scale and suspended from pulleys as shown.

What is the reading on the scale?
A) 0 N B) 2.5 N C) 5 N D) 10 N E) 25 N

Problems (20 points each):Show your work clearly and completely for each of the following problems. Please do one problem per page in the answer booklet and write the problem number on the top of page.

11. A tennis ball is shot vertically upward from the surface of an atmosphere-free planet with an initial speed of 20.0 m/s. One second later, the ball has an instantaneous velocity in the upward direction of 15.0 m/s.
A)How long does it take the ball to reach its maximum height?
B)How high does the ball rise?
C)What is the magnitude of the acceleration due to gravity on the surface of this planet?
D)Determine the velocity of the ball when it returns to its original position. Note: assume the upward direction is positive.
E)How long has the ball been in the air when it returns to its original position?
12. / A basketball is launched with an initial speed of 8.0 m/s and follows the trajectory shown. The ball enters the basket 0.96 s after it is launched. What are the distances x and y? Note: The drawing is not to scale.

13. / A 4.0-kg block is connected by means of a massless rope to a 2.0-kg block as shown in the figure. If the 2.0-kg block is accelerating at 2.5 m/s2 downward,:
A)draw the free body diagram for each block.
B)determine the tension in the rope.
C)determine the coefficient of sliding friction between the 4.0-kg block and the surface.

Answer Key

1. / E
2. / C
3. / D
4. / D
5. / A
6. / D
7. / B
8. / D
9. / D
10. / C
11. / C
12. / E
13. / A
14. / B
15. / C
16. / C
17. / E

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