01prob_10

# 01prob_10 - Assigment#1 Page 1 of 3 UC Davis Physics 9A...

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

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.

Unformatted text preview: Assigment #1, 4/1/10 Page 1 of 3 UC Davis Physics 9A Assignment #1 Cole [1.3]   The speed of light is 3 ª 10 8  m/s.  It takes light   t = d v = 1 ft ( ) 0.305 m/ft ( ) 3 × 10 8 m/s = 1.0 ns  to travel  one foot. [1.8]   180,000 fl / fn = 180,000 fl / fn 1/8 mi/ fl 14 D/ fn × 24 hr/D  = 67 mi/hr. [1.12]     t  = (365.24 D/yr)(24 hr/D)(3600 s/hr) = 3.1557 ª 10 7  s.   e = true value-approx value true value × 100%   õ   e = 3.1557 − 3.1416 3.1557 × 100%  = 0.4 % [1.19]  Let's estimate how many sheets there might be.  A ream (500 sheets) of paper is about 2 in  thick.  From the dimensions of the box there must be two stacks of paper 9 in thick í 10 in  õ 10  reams  = 5000 pieces of paper so we are within a factor of 2 of 10,000 for our guess.  Hence it  must be 10,000 of light weight paper and certainly not a million. [1.28]   A ream (500 sheets) of paper is about 2 in thick.  Estimate that a \$500 stack would be  about 5 cm thick.  õ  \$500 ª20/m =  \$10,000/m.  The moon is 4 ª 10 8  m away  õ   (\$10 4 /m)(4 ª 10 8 m)= \$4 ª 10 12   =  4 T\$  = 4 (terabucks).  The cost of building a spaceship and  sending it could well cost several billion dollars of today's money, but this is still well below a  trillion dollars. [1.41]   The total displacement is the sum of the individual displacements:  Î r√ = Îr√ 1  + Îr√ 2  + Îr√ 3  .   Resolving into Cartesian components with east as the  x-direction and north as the  y- direction, Δ r 1 = ˆ i + 3.25 ˆ j Δ r 2 = − 4.75 ˆ i + ˆ j Δ r 3 = ˆ i − 1.5 ˆ j Δ r = − 4.75 ˆ i + 1.75 ˆ j    Δ...
View Full Document

## This note was uploaded on 09/28/2011 for the course PHY 9A taught by Professor Svoboda during the Spring '08 term at UC Davis.

### Page1 / 3

01prob_10 - Assigment#1 Page 1 of 3 UC Davis Physics 9A...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online