Stadle we wton's law of gravitation
and show that F=Gm1m2/d2

B. convex since the words are bigger

It may possibly be c i think |-/

I'm not sure what your asking buddy.. but i know that you can weld two peices of steel by pure force and pressure.

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.