It requires 2.500 joules to raise a certain amount of water
(c = 4.186 jlg°c) from 20.0°c to 60.0°c.

what is the mass of the water that is being heated?
o 159
o 409
o 639
o 809

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.