Chapter 1 Quick Review - Department of Physics



TA: Tomoyuki Nakayama March 29th – March 30th, 2010

PHY 2048: Physics 1 with Calculus, Spring 2010

Review: Chapter 13.1-13.

The purpose of this review is to refresh your memory. Physics is a cumulative subject, so make it sure that you understand basic concepts and typical problem solving techniques in previous chapters before moving on to a new chapter.

________________________________________________________________________________

A . Newton’s Law of Gravitation & Superposition Principle

In the right figure, particles are located at the center and on the perimeter of a square of length L. Find the net gravitational force on the particle at the center

A particle of mass m = 2 kg is a distance d = 0.5 m from one end of a uniform rod with length L = 1.5 m and mass M = 5 kg. What is the magnitude of the gravitational force on the particle from the rod?

B. Gravitational Potential Energy

The figure on the right shows two concentric spherical shells with radii R1 and R2 and masses M1 and M2. A particle of mass m is brought to the center of the shells from infinity. Find the net work.

C. Kepler’s Laws

A certain triple-star system consists of two stars each of mass m, revolving in the same circular orbit of radius r around a certain star of mass M. The two orbiting stars are always at opposite ends of a diameter of the orbit. Derive the expression for the period of revolution of the stars.

TA: Tomoyuki Nakayama March 29th– March 30th, 2010

PHY 2048: Physics 1 with Calculus, Spring 2010

Practice Exam Problems (Chapter 13.1-13.9)

Working on this problem set is optional, but it is strongly recommended. It is highly likely that some of these problems will appear in the exams. Do it on a weekly basis. Cramming is tiring and sometimes it ends up in a disaster.

________________________________________________________________________________

1. Three particles, two with mass m and one with mass M, might be arranged in any of the four configurations known below. Rank the configurations according to the magnitude of the gravitational force on M, least to greatest. (Superposition) a. 1, 2, 3, 4 b. 2, 1, 3, 4 c. 2, 1, 4, 3, d. 2, 3, 1, 4 e, 2, 3, 4, 1

2. A spherical shell has inner radius R1, outer radius R2 and mass M, distributed uniformly throughout the shell. The magnitude of the gravitational force exerted on the shell by a point mass particle of m, located a distance d from the center, inside the inner radius, is: (Gravitation due to a Spherical Shell) a. 0 b. GMm/R12 c. GMm/d2 d. GMm/(R22-d2) e. GMm/(R1-d)2

3. Each of the four corners of a square with edge length a is occupied by a point mass m. There is a fifth mass, also m, at the center of the square. To remove the mass form the center to a point far away the work that must be done by an external agent is given by: (Gravitational Potential Energy) a. 4Gm2/a b. -4Gm2/a c. 4√2Gm2/a d. -4√2Gm2/a e. 4Gm2/a2

4. The orbit of a certain satellite has a semimajor axis of 1.5×107 m and an eccentricity of 0.20. Its perigee(minimum distance) and apogee (maximum distance) are respectively: (Kepler’s Law) a. 1.2×107 m, 1.8×107 m b. 3.0×107 m, 1.2×107 m c. 9.6×107 m, 1.0×107 m d. 1.0×107 m, 1.2×107 m e. 9.6×107 m, 1.8×107 m

5. A projectile is fired straight upward from Earth’s surface with a speed that is half the escape speed. If R is the radius of Earth, the highest altitude reached, measured from the surface is: (Escape Speed) a. R/4 b. R/3 c. R/2 d. R e. 2R

6. An artificial satellite of Earth nears the end of its life due to air resistance. While still in orbit: (Satellite’s Motion) a. it moves faster as the orbit lowers b. it moves slower as the orbit lowers c. it slowly spirals away form Earth d. it moves slower in the same orbit but with a decreasing period e. it moves faster in the same orbit but with an increasing period

Answers: 1-b 2-a 3-c 4-a 5-b 6-a

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download