Homework 2 Answer Key
Chapter 3
" 0.01m %
' = 0.0895m
# 1cm &
" 0.01m %" 1mm %
c) 129cm$
'$
' = 1290mm
# 1cm &# 0.001m &
! 72. a) 78.3in. ! 2.54cm " = 199cm
#
$
% 1in. &
" 12in.%" 2.54cm %
c) 336 ft$
' = 1.02x10 4 cm
'$
#
# 1 ft & 1in &
"
%
b) 1298.4g$ 1kg ' = 1.2984kg
#1000g &
"
%
d) 2452mL$ 0.001L ' = 2.452L
# 1mL &
68. a) 8.95cm$
!
!
" 453.59 g %
80. 1.6lb$
' = 7.3x10 2 g
# 1 lb &
"
1m %
' = 407m
# 1.094 yd &
!
b) 445yd$
!
"
%"
%
d) 45.3in.$ 2.54cm '$ 10mm ' = 1.15x10 3 mm
# 1in &# 1cm &
!
!
" 0.6214mi %" 1hr %
82. 195km$
'$
' = 5.0hr
# 1km &# 24mi &
!
!
" 3.785L %"1000mL %"1cm 3 %
3
3
84. 2.0gal$
'$
' = 7.6x10 cm
'$
# 1gal &# 1L &# 1mL &
!
"1cm 3 %" 0.7857g %
28.56mL$
'$
3 ' = 22.44g
# 1mL &# 1cm &
100.
" 1cm 3 %
3
6.54g$
' = 8.23cm = 8.23mL
# 0.7857g &
!
64. a) 38.9ºC
b) -460ºF
c) -54ºF
d) 0.15ºC
66. 57ºC and 330 K
68. 277.4ºC and 531.3ºF
86. The iron changed temperature by a greater amount, even though they both lost the same amount of
heat (implied by the fact that the two containers were identical and the amount of time passed was the
same.) This is expected because iron has a lower heat capacity (or, specific heat) than water, and
therefore its temperature drops by a larger amount when it loses the same amount of heat.
A. 1)
2)
!
70.0 lb " 7 days %" 1 kg %
$
'$
' = 222kg /week
day # 1 week &# 2.205 lb &
" 1000 L %" 1cL %
0.66 kL$
'$
' = 6.6x10 4 cL
# 1 kL &# 0.01L &
3)
!
!
4)
500.0 cg " 1 mL %" 0.01 g %" 1mg %
6
$
'$
'$
' = 5.000x10 cg /mL
mL # 0.001 L &# 1 cg &# 0.001g &
5)
56.5 mg " 10 -6 g %" 1 kg %" 1 mm3 %" 0.013 m3 %
-5
$
'$
'$
' = 5.65x10 kg/L
'$
mm3 # 1 mg &#1000 g &# 0.0013 m3 &# 1 cm3 &
!
" 1 mL %" 1cm3 %" 0.013 m3 %" 1 mm3 %"14000 cells %
E. 5.0 L$
'$
' = 7.0x1010 cells
'$
'$
'$
# 0.001L &#1 mL &# 1cm3 &# 0.0013 m3 &# mm3 &
!
G. The block of silver will be at a higher temperature after absorbing the heat because it has a lower heat
capacity and therefore the temperature changes more radically than that of the water (which has a high
specific heat and is less “sensitive” to heat changes.)