Initial State: An 8-month old child is at rest at the bottom of a staircase. Final State: The 8-month old child is at rest at the top of the staircase. Notes: The system includes the child and earth. The child uses the steps to slowly crawl up the staircase

Answer sample (c); // would be best because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest;

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.

Your answer would be the sun