home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Investigating Forces & Motion
/
Investigating Forces and Motion (1998)(Granada Learning).iso
/
data
/
topic11
/
example.dat
< prev
next >
Wrap
INI File
|
1998-02-16
|
1KB
|
41 lines
[general]
[page1]
type:1
caption:\
The graphs below show the results of tensile tests on five different \
materials.<p>\
Drag the arrows to match the materials to their test results.<p>
feedback:\
Correct. The materials behave very differently in tensile tests. \
Copper is ductile beyond its elastic limit, glass is brittle, \
polythene can be stretched plastically to many times its original \
length and rubber is highly elastic.<p>
source:11ex1a1, 11ex1d1, 11ex1c1, 11ex1b1
target:11ex1c, 11ex1a, 11ex1b, 11ex1d
[page2]
type:0
caption:\
A spring obeys Hooke's law up to a load of 100 N. The unloaded spring \
is 0.20 m long.<p>\
When a 50 N load is hung from the spring it extends to 0.30 m. What \
will the length of the spring be when it carries an 80 N load?<p>\
When the spring obeys Hooke's law <I>F = kx</I>.<p>\
The extension, <I>x</I> = stretched length - unstretched length<p>\
= 0.30 - 0.20<p>\
= 0.10 m<p>\
<I>F</I> = 50 N<p>\
Therefore <I>k</I> =<I>F/x</I><p>\
= 50/0.10<p>\
= 500 N/m<p>\
So when <I>F</I> = 80 N,<p>\
<I>F</I>= <I>kx</I><p>\
80 = 500<I>x</I><p>\
<I>x</I> = 80/500<p>\
= 0.16 m<p>\
Thus the length of the spring = 0.20 + <I>x</I><p>\
= 0.20 + 0.16<p>\
= 0.36 m.<p>