Assignment #1 Problems
For Exam 1, you will be expected to do problems of difficulty similar to those below without reference to the text or to any notes. Make sure that you can do this before you move on to the next assignment!
Graded Homework Problems
Do Assignment 1A and Assignment 1B at www.masteringphysics.com . Remember, when you register the first time, use ESUPHYSICS1612005 for the Course ID. You can choose your own Student ID, but make sure that it is between 5 and 12 characters in length. You can do the assignment entitled Introduction to MasteringPhysics if you wish, but it is not required. This assignment is designed simply to familiarize you with the way that the program works.
Mandatory Homework Problems
(1) Suppose that two quantities A and B have different dimensions. Determine which of the following arithmetic operations could be physically meaningful: (a) A + B (b) A/B (c) B - A (d) AB
(2) A section of land has an area of 1 square mile and contains 640 acres. Determine the number of square meters in 1 acre.
(3) Consider the following combinations of signs and values for the velocity and acceleration of a particle with respect to a one-dimensional axis:
(velocity, acceleration) = (a) (positive, positive), (b) (positive, negative), (c) (positive, zero), (d) (negative, positive), (e) (negative, negative), (f) (negative, zero), (g) (zero, positive), (h) (zero, negative).
Describe what a particle is doing in each case, and give a real life example for an automobile on an east-west one-dimensional axis, with east considered the positive direction.
(4) A person walks first at a constant speed of 5.00 m/s along a straight line from point A to point B and then back along the line from B to A at a constant speed of 3.00 m/s. What is (a) her average speed over the entire trip? (b) her average velocity over the entire trip?
(5) Automotive engineers refer to the time rate of change of acceleration as the "jerk". If an object moves in one dimension such that its jerk J is constant, (a) determine expressions for its acceleration ax(t), velocity vx(t), and position x(t), given that its initial acceleration, velocity, and position are axi , vxi , and xi , respectively. (b) Show that ax2 = axi2 + 2J(vx - vxi) .
(6) A commuter train travels between two downtown stations. Because the stations are only 1.00 km apart, the train never reaches its maximum possible cruising speed. During rush hour the engineer minimizes the time interval Dt between the two stations by accelerating for a time interval Dt1 at a rate a1 = 0.100 m/s2 and then immediately braking with acceleration a2 = -0.500 m/s2 for a time interval Dt2. Find the minimum time interval of travel Dt and the time interval Dt1.
(7) Two neutral atoms have the same atomic number, but different mass numbers. Describe how they differ. If they had the same mass number, but different atomic numbers, how would they differ?
(8) Describe a situation in which the predictions of Special Relativity would agree significantly better with experiment than would those of Classical Mechanics. In the situation that you describe, estimate the percentage by which the predictions of the two theories would differ.
(9) Describe a situation in which the predictions of Quantum Mechanics would agree significantly better with experiment than would those of Classical Mechanics. In the situation that you describe, estimate the percentage by which the predictions of the two theories would differ.
(10) How many different "flavors" of quarks are there, and what are their names? Of the following particles, which are believed to be composed of quarks: proton, neutron, electron, photon. For the particles that are composed of quarks, what quarks are they composed of?