If a truck is moving in a straight line and has a frictional force of 7N acting against it, what is the magnitude of the force necessary to keep the truck moving with no
acceleration?

Hypothesis. why don’t you know this? i learned this stuff in like 5th grade

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.

Ithink c because you have to work to become goid