Sears - ex. resolvidos

Física I – Sears, Zemansky,
Young & Freedman.

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

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)

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.
3

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

1.2:

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
3

g  1 kg   100 cm 
4 kg
11.3
×
3
 1000 g  ×  1 m  =1.13 × 10 m 3 .

 cm 



1.4:

1.5:

1.6:

(327 in )× (2.54 cm in ) × (1 L 1000 cm ) = 5.36 L.
3

3

3

 1000 L   1 gal   128 oz.   1 bottle 
1 m3 × 
 1 m 3  ×  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.

1.8:

180,000

1.9:

15.0

furlongs  1 mile   1 fortnight   1 day  mi ×
 8 furlongs  ×  14 day  ×  24 h  = 67 h .



fortnight 




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 


3

 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 =