p201f04-homework01-sol

# p201f04-homework01-sol - Version One Homework 1 Heinz 81204...

This preview shows pages 1–2. Sign up to view the full content.

Version One – Homework 1 – Heinz – 81204 – Aug 30, 2004 1 This print-out should have 14 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. The due time is Central time. Serway CP 01 03 01:04, trigonometry, multiple choice, > 1 min, fixed. 001 (part 1 of 1) 10 points Consider the expression 2 π s l g , where l is length and g is gravitational ac- celeration in units of length divided by time squared. Evaluate its units. 1. m s 2. s m 3. m 2 4. s 2 5. m 6. s correct 7. m s · 2 8. s m · 2 Explanation: The unit of length ( l ) is m and the unit of gravitational acceleration ( g ) is m s 2 . 2 and π are constants, so the unit of s l g is r m m s 2 = r m ÷ m s 2 = r m · s 2 m = s 2 = s τ = 2 π s l g is the formula for the period of a pendulum (the time for one complete oscillation). Beach Sand 01:05, trigonometry, numeric, > 1 min, nor- mal. 002 (part 1 of 2) 5 points Grains of fine beach sand are assumed to be spheres of radius 35 μ m. These grains are made of silicon dioxide which has a density of 2600 kg / m 3 . a) What is the mass of each grain of sand? Correct answer: 4 . 66945 × 10 - 10 kg. Explanation: Since ρ = m V , then each grain has a mass of m = ρ V = ρ 4 3 π r 3 = ( 2600 kg / m 3 ) 4 3 π (35 μ m) 3 × 1 m 10 6 μ m 3 = 4 . 66945 × 10 - 10 kg . 003 (part 2 of 2) 5 points Consider a cube whose sides are 0 . 15 m long. b) How many kg of sand would it take for the total surface area of all the grains of sand to equal the surface area of the cube? Correct answer: 0 . 004095 kg. Explanation: Each grain of sand has a surface area of A g = 4 π r 2 , and the cube has a surface area of A c = 6 a 2 , so the required number of grains of sand is n = A c A g = 6 a 2 4 π r 2 .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern