Reviews the approach taken in problems such as this one. a bird watcher meanders through the woods, walking 0.916 km due east, 0.918 km due south, and 3.52 km in a direction 49.7 ° north of west. the time required for this trip is 1.750 h. determine the magnitudes of the bird watcher's (a) displacement and (b) average velocity.

Displacement: 2.230 km    Average velocity: 1.274

Explanation:

Let's represent displacement by the letter S and the displacement in direction 49.7° as A. Displaement is a vector, so we need to decompose all the bird's displacement into their X-Y compoments. Let's go one by one:

0.916 km due east is an horizontal direction and cane be seen as  direction towards the negative side of X-axis.0.928 km due south is a vertical direction and can be seen as a direction towards the negative side of Y-axis.3.52 km in a direction of 49.7° has components on X and Y  axes. It is necessary to break it down using trigonometry,

First of all. We need to sum all the X components and all the Y componets.

∑ ⇒  ∑

∑

∑ ⇒ ∑

∑

The total displacement is calculated using Pythagoeran therorem:

⇒

With displacement calculated, we can find the average speed as follows:

 ⇒  

1) when you rub your hands together quickly, the kinetic energy is converted to mechanical energy.2) thermal energy from the sun travels to earth as infrared waves.3) energy is transferred through the matter of space by electromagnetic waves. 4) when a match is burned, chemical potential energy is converted to thermal and radiant energy. 5) seismicwaves are caused by back and forth movement , or vibration, of an object. 6) mechanicalenergy in an engine changes thermal energy into kinetic energy to make a car move.