Resoluçã sears

Física I – Sears, Zemansky, Young & Freedman.

PHYSICS ACT. http//physicsact.wordpress.com Capítulo 1

1.1: 1 mi × (5280 ft mi ) × (12 in. ft ) × (2.54 cm in .) × 1 km 105 cm = 1.61 km Although rounded to three figures, this conversion is exact because the given conversion from inches to centimeters defines the inch.

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1.2:

 1000 cm 3   1in  3 0.473 L ×      1 L  ×  2.54 cm  = 28.9 in .    

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1.3: The time required for light to travel any distance in a vacuum is the distance divided by the speed of light; 103 m = 3.33 × 10− 6 s = 3.33 × 103 ns. 8 3.00 × 10 m s g  1 kg   100 cm  4 kg 11.3 × 3  1000 g  ×  1 m  =1.13 × 10 m 3 .    cm    
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1.4:

1.5:

(327 in )× (2.54 cm in ) × (1 L 1000 cm ) = 5.36 L.
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1.6:

 1000 L   1 gal   128 oz.   1 bottle  × × ×  . 1 m3 ×  3          1 m   3.788 L   1 gal   16 oz.  = 2111.9 bottles ≈ 2112 bottles

The daily consumption must then be bottles  1 yr  bottles 2.11 × 10 3 ×  365.24 da  = 5.78 da .  yr  

1.7:

(1450 mi hr ) × (1.61 km mi) = 2330 km hr . 2330 km hr × (103 m km )× (1 hr 3600 s ) = 648 m s. furlongs  1 mile   1 fortnight   1 day  mi ×  8 furlongs  ×  14 day  ×  24 h  = 67 h .      fortnight      

1.8:

180,000

1.9:

15.0

km  1 mi   3.788 L  mi × ×  1 gal  = 35.3 gal .  L  1.609 km   

 mi  1.10: a)  60   hr 

 1h       3600 s 

 5280 ft  ft   1 mi  = 88 s   

m  ft   30.48 cm   1 m  b)  32 2    1ft   100 cm  = 9.8 s 2    s  

g   100 cm   c) 1.0   cm 3   1 m  

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 1 kg  3 kg   1000 g  = 10 m 3   

1.11: The density is mass per unit volume, so the volume is mass divided by density. V = 60 ×103 g 19.5 g cm 3 = 3077 cm 3 4 Use the formula for the volume of a sphere, V = πr 3 , 3 1/ 3 to calculate r : r = (3V 4π ) = 9.0 cm

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1.12:

(3.16 × 10 7 s − π