A tractor T is pulling a trailer M with a constant velocity. If the velocity is $20$ m$/$s and M $=$

$200$ kg and T $=500$ kg$,$ then the force on the trailer due to the tractor is $($assume there is no

friction or air resistance$)$

A$)35$ N forward

$450$ N backward.

$200$ N backward.

$0.$

E$)$

$600$ N forward.