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Young and Freedman - University Physics 12/e (Homework)

James Finch

Physics - College, section 1, Fall 2010

Instructor: Dr. Friendly

Current Score: 3/20

Due: Sunday, January 9, 2011 19:00 EST

About this Assignment

Question
Points
1 2 3 4 5
0/2 3 0/3 0/5 0/7
Total
3/20

Description

Here are some textbook questions from University Physics 12/e by Young and Freedman published by Addison Wesley. Click here for a list of all of the questions coded in WebAssign.


Instructions

This demo assignment allows many submissions and allows you to try another version of the same question for practice.



1. 0/2 points All Submissions Notes Question: YF12 4.P.004.
Question part
Points
Submissions
1 2
0/1 0/1
5/50 1/50
Total
0/2
 
A man is dragging a trunk up the loading ramp of a mover's truck. The ramp has a slope angle of 20.0°, and the man pulls upward with a force vector F whose direction makes an angle of θ = 29.0° with the ramp.
(a) How large a force vector F is necessary for the component Fx parallel to the ramp to be 77.0 N?
Enter a number.
Your answer is incorrect. N

(b) How large will the component Fy perpendicular to the ramp then be?
Enter a number.
Your answer is incorrect. N


2. 3/3 points All Submissions Notes Question: YF12 7.P.018.
Question part
Points
Submissions
1 2 3
1 1 1
1/50 1/50 8/50
Total
3/3
 
A slingshot will shoot a 11-g pebble 27.0 m straight up.
(a) How much potential energy is stored in the slingshot's rubber band?
Enter a number.
Your answer is correct. J

(b) With the same potential energy stored in the rubber band, how high can the slingshot shoot a 29 g pebble?
Enter a number.
Your answer is correct. m

(c) What physical effects did you ignore in solving this problem? (Select all that apply.)

Your answer is correct.




3. –/3 points Notes Question: YF12 12.P.025.
Question part
Points
Submissions
1 2 3
0/1 0/1 0/1
0/50 0/50 0/50
Total
0/3
 
Use the following result of Example 12.5 (Section 12.3)
v_1 = sqrt((2GM)/R)
(where v1 is the initial speed needed for a body to escape from the surface of a spherical mass M with radius R) to calculate the following.
(a) The escape speed for a spacecraft from the surface of Mars. Use the data in Appendix F.
Enter a number.
 m/s

(b) The escape speed for an object from the surface of Jupiter.
Enter a number.
 m/s

(c) Why is the escape speed for a spacecraft independent of the spacecraft's mass?


4. –/5 points Notes Question: YF12 13.P.010.
Question part
Points
Submissions
1 2 3 4 5
0/1 0/1 0/1 0/1 0/1
0/50 0/50 0/50 0/50 0/50
Total
0/5
 
Jerk. A guitar string vibrates at a frequency of 410 Hz. A point at its center moves in SHM with an amplitude of 2.0 mm and a phase angle of zero.
(a) Write an equation for the position of the center of the string as a function of time t. (Keep the value of the amplitude in mm, and use pi for π, t for t as appropriate).
x(t) =
Enter a mathematical expression.
Click here to preview your answer.

(b) What are the maximum values of the magnitudes of the velocity and acceleration of the center of the string?
velocity
Enter a number.
 m/s
acceleration
Enter a number.
 m/s2

(c) The derivative of the acceleration with respect to time is a quantity called the jerk. Write an equation for the jerk of the center of the string as a function of time (Keep the value of the amplitude in mm, and use pi for π, t for t as appropriate).
j(t) =
Enter a mathematical expression.
Click here to preview your answer.

Find the maximum value of the magnitude of the jerk.
Enter a number.
 mm/s3

Click here for help with symbolic formatting.

5. –/7 points Notes Question: YF12 22.P.008.
Question part
Points
Submissions
1 2 3 4 5 6 7
0/1 0/1 0/1 0/1 0/1 0/1 0/1
0/50 0/50 0/50 0/50 0/50 0/50 0/50
Total
0/7
 
The three small spheres shown in the figure below carry charges q1 = 4.50 nC, q2 = -7.90 nC, and q3 = 2.75 nC.
Find the net electric flux through each of the following closed surfaces shown in cross section in the figure.
(a) S1
Enter a number.
 N · m2/C 		(b) S2
Enter a number.
 N · m2/C
(c) S3
Enter a number.
 N · m2/C 		(d) S4
Enter a number.
 N · m2/C
(e) S5
Enter a number.
 N · m2/C

(f) Do your answers to parts (a) through (e) depend on how the charge is distributed over each small sphere?
    



Why or why not?

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