Force to slam explosively causing wreckage (7)
I believe the answer is:
flotsam
'wreckage' is the definition.
(flotsam is a kind of wreckage)
'force to slam explosively' is the wordplay.
'force' becomes 'F' (symbol used in Physics e.g. f=ma).
'explosively' indicates anagramming the letters.
'to'+'slam'='toslam'
'toslam' with letters rearranged gives 'lotsam'.
'f'+'lotsam'='FLOTSAM'
'causing' acts as a link.
(Other definitions for flotsam that I've seen before include "Wreckage found floating" , "Things going adrift" , "Washed-up wreckage" , "Shipwreck goods floating" , "Wreckage adrift at sea" .)