The following is the distance-times table of an object in motion:
Time in seconds                         Distance in metres
$0$                                                  $0$
$1$                                                  $1$
$2$                                                  $8$
$3$                                                  $27$
$4$                                                  $64$
$5$                                                  $125$
$6$                                                  $216$
$7$                                                  $343$
$(a)$ What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
$(b)$ What do you infer about the forces acting on the object?

A hammer of mass $500g,$ moving at $50{ms}^{-1},$ strikes a nail. The nail stops the hammer in a very short time of $0.01s.$ What is the force of the nail on the hammer?