00306    a2200109   4500020001500000082001300015100002400028245007200052260004400124300001600168650001200184  a0749251336  a530bOPE  aThe open university  aScience b a second level coursebdiscovering physics b unit 10,11  aKeynesbThe open universityc1994g1994  a78p.c30cm.  aPhysics