Week 5 Homework
Due May 6. 1. Work (a) Give a sports example of positive work. (b) Give a sports example of something that is tiring but does not involve work. (c) Give a sports example where the force and motion are not parallel, so only the paralle
Solutions HW 12
Chapter 8: Exc: 11,12,13,14
12: As there are four distinguishable states of these electrons, four
electrons can be placed in each level.
14.It can become more conducting as thermal energy shifts more
electrons to the conduction ban
Soultions HW 11
Exc. 4,8,14,24; prob: 2,6
Case : 2
4. A very small current can flow through the bird as its two legs are
quite close to each other on the wire and the potential drop across it
is very small.
8. The end which is connected to highe
Solutions HW 13
Chapter 11: Exc: 18,20,24
Ex 18:A magnetic field pushes a moving charged particle at right angles to its
velocity. The particle therefore does not move in the direction of the force on it. In
fact, it moves at right angles to
Solutions HW 14
Chapter 11: Ex: 26,30
Exc 26Aluminum trays would reflect the microwaves and make it difficult to cook the
Ex: 30: Microwaves cannot respond to holes in the metal that are significantly smaller
than their wavelengths.
P18 Solutions Problem set 8
Chapter 4: Exc 12, 18, 20 and Problem 2
Chapter 5: Exc 8,14,18,34,54
Chap 4 Exc 12:
At high altitude, the air is less dense so filling the bottle with high altitude air means
that the bottle contains relatively few air molecule
Physics 18 Quiz II
1. When you walk on a sidewalk in which direction is the force of friction?
(a ) upwards, (b) in the direction you are moving, ( c) opposite to the direction you are
moving (d) downwards.
1. *Correct answer (b). Reasoning : If
Solutions Chapter 7:
Exc 2, 4, 10,14
Cases 1, 4
The rack is a pendulum and its period depends only on its length and on the
strength of gravity.
The restoring force acting on the tree is proportional to how far it is bent away from its
Week 1 Homework
Due Monday April 7. 1. Give a sports example of an object that travels a large distance but has a small displacement. 2. Can you give a sports example wherein the acceleration of an object is opposite to the direction of its velocity?
Week 4 Homework
Due April 28. 1. The top figure on the next page shows snapshots of a golf swing taken at regular intervals. Call the forward direction of the swing the positive direction for increasing angle. (a) When is the angular velocity largest
Week 3 Homework
Due April 21. 1. The textbook says "this process of adding the mass of a large body to the mass of a smaller one is very important in many sports." What example does the textbook use to illustrate this principle? Give an example from
Week 2 Homework
Due April 14. 1. Why is the optimal launch angle in shot put slightly less than 45 ? According to the textbook, which factor is more important than launch angle in determining the range of the shot put? Which figure supports this asse
Solutions problem set 10:
Chapter 8: Ex: 6,8,14,34
problems: 2,4 5
6. A normal bowling ball is electrically neutral-it has as many positive as negative
charges. Thus the attractive and repulsive forces between the balls cancel
8. The energy becomes electr