Richards, Jon,  1970- <br/><br/>
Forces and simple machines. 

 - London :  Watts,  2000. 
 - 32p. :  col. ill. ;  29 cm. 
 - Science factory .
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0749634359 9780749634353 
<br/><br/><label>Nat. Bib. No.: </label>GB99U7371  bnb 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Force and energy--Juvenile literature.<br/>Force and energy--Experiments--Juvenile literature.<br/>Simple machines--Juvenile literature.