Looking at waves a and b. which description correctly describes the waves?

a) wave a has twice the energy because it has a frequency twice as large.

b) wave a has twice the energy because it has an amplitude twice as large.

c) wave b has twice the energy because it has an amplitude twice as large.

d) waves a and b gave the same energy because they have the same amplitude.

From what I remember from this unit of math, the answer would be C) Wave B has twice the energy because it has an amplitude twice as large.

Anybody can correct me if I'm wrong but I think I'm correct.

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.