Colllege Physics I -- PHY 2053

College Physics I -- PHY 2053

Test I January 22, 2013 *** FORM A

Instructions: Clearly bubble in your name and Z number on the Scantron. Also clearly indicate the form you answered. You can keep the test to check your answers later.

Formulas:

Components of a vector:

Ax = A cos q

Ay = A sin qMagnitude and direction:

A = sqrt (Ax2 + Ay2)

q = tan-1(Ay/Ax)

One-dimensional motion with constant acceleration:

v = v0 + at

x = x0 + v0t + 1/2at2

v2 = v02 + 2a(x x0).

Vector A has magnitude 4.4 m and direction 110o relative to the positive x-axis. Vector B has magnitude 2.1 m and direction 80o relative to the positive x-axis. Questions 1-5 refer to this situation.

1. Vector A is located in:

a. Quadrant 1;

b. Quadrant 2;

c. Quadrant 3;

d. Quadrant 4.

2. The components of vector B obey the inequalities:

a. Bx > 0, By > 0;

b. Bx < 0, By > 0;

c. Bx > 0, By < 0;

d. Bx < 0, By < 0.

3. Vector A has magnitude and direction:

a. -4.4m, 110o;

b. -4.4 m, 290o;

c. 4.4 m, 110o;

d. 4.4 m, 290o.

4. The resultant R = A + B has magnitude (in m):

a. 0 < R < 2.0;

b. 2.0 < R < 4.0;

c. 4.0 < R < 6.0;

d. R > 6.0.

5. The direction of the resultant R = A + B (relative to the positive x-axis) is:

a. 0 o < q < 90 o;

b. 90 o < q < 180 o;

c. 180 o < q < 270o;

d. 270 o < q < 360o.

Vector C has components Cx = -2.0 m and Cy = 0.0 m. Questions 6-7 refer to this vector.

6. Vector C is located along the:

a. positive x-axis;

b. negative x-axis;

c. positive y-axis;

d. negative y-axis.

7. The direction of vector C (relative to the positive x-axis) is:

a. 0o;

b. 90o;

c. 180o;

d. 270o.

8. Two vectors have magnitudes 4 m and 8 m. Which one of the following values is not a possible magnitude for their resultant?

a. 3 m;

b. 5 m;

c. 8 m;

d. 11 m.

9. Two vectors have magnitudes 5 m and 12 m. Their resultant has a magnitude of 13 m. The angle between the two vectors must be:

a. 0o;

b. 90o;

c. 180o;

d. 360o.

10. How many of the following are vector quantities: velocity, acceleration, mass, weight?

a. one;

b. two;

c. three;

d. four.

11. I drive from home to FAU and back. Consider the distance traveled by my car and its displacement, both for the round trip.

a. Distance = 0, displacement = 0;

b. Distance is not zero, displacement = 0;

c. Distance = 0, displacement is not zero;

d. Distance is not zero, displacement is not zero.

12. A particle is moving in the negative x-direction with an acceleration in the positive x-direction.

a. The particle is speeding up;

b. The particle is slowing down;

c. The particle is changing direction;

d. This situation is physically impossible.

A 5-kg ball is thrown straight up in the air with an initial speed of 40 m/s. Ignore air resistance and take the x-axis to be pointing up. Questions 13-26 refer to this situation.

13. After its release and before it hits the ground, the ball is in free fall:

a. Only while moving up;

b. Only while moving down;

c. At the highest point;

d. At all times.

14. While it is moving up, the balls velocity is:

a. Pointing up;

b. Pointing down;

c. Zero.

15. While it is moving up, the balls acceleration is:

a. Pointing up;

b. Pointing down;

c. Zero.

16. At the highest point, the balls velocity is:

a. Pointing up;

b. Pointing down;

c. Zero.

17. At the highest point, the balls acceleration is:

a. Pointing up;

b. Pointing down;

c. Zero.

18. If the balls mass is doubled, but the initial speed stays the same, the time to reach the highest point will:

a. Increase;

b. Decrease;

c. Remain the same.

19. If the balls initial speed is doubled, but its mass stays the same, the time to reach the highest point will:

a. Increase;

b. Decrease;

c. Remain the same.

20. How long does it take the ball to reach its highest point?

a. Less than 1.5 seconds;

b. Between 1.5 and 3 seconds;

c. Between 3 and 4.5 seconds;

d. More than 4.5 seconds.

21. How high above the starting position is the highest point?

a. Less than 15 m;

b. Between 15 and 30 m;

c. Between 30 and 45 m;

d. More than 45 m.

22. 3.5 seconds after it was thrown up, the ball is:

a. moving up;

b. moving down;

c. at rest;.

23. When the ball passes through the starting point again, its speed will be:

a. Less than 40 m/s;

b. Exactly 40 m/s;

c. More than 40 m/s.

24. When the ball passes through the starting point again, its velocity will be:

a. Less than 40 m/s;

b. Exactly 40 m/s;

c. More than 40 m/s.

25. When the ball passes through the starting point again, its displacement is:

a. Positive;

b. Zero;

c. Negative.

26. The ball is at a height of 25 m above its starting point:

a. Never;

b. Once;

c. Twice.

27. The quantity a.t (acceleration times time) has the same units as:

a. Speed;

b. Distance;

c. Distance squared;

d. None of the above.

28. In a position-time diagram, the slope of the curve represents:

a. Position;

b. Velocity;

c. Acceleration;

d. Displacement.

29. In a velocity-time diagram, the slope of the curve represents:

a. Position;

b. Velocity;

c. Acceleration;

d. Displacement.

30. In a velocity-time diagram, the displacement is found by determining:

a. The intercept of the curve;

b. The slope of the curve;

c. The area underneath the curve.

Consider the velocity-time diagram in the sketch on the back of this page. Questions 31-34 refer to this situation.

31. At the point indicated by A, the particles velocity is:

a. Positive;

b. Negative;

c. Zero.

32. At the point indicated by A, the particles acceleration is:

a. Positive;

b. Negative;

c. Zero.

33. The particles velocity is zero:

a. At A;

b. At B;

c. At C;

d. At D.

34. Between points A and B the particles displacement is:

a. Positive;

b. Negative;

c. Zero.

PAGE 1