a) Let's call x the direction parallel to the river and y the direction perpendicular to the river.
Dave's velocity of 4.0 m/s corresponds to the velocity along y (across the river), while 6.0 m/s corresponds to the velocity of the boat along x. Therefore, the drection of Dave's boat is given by:

relative to the direction of the river.
b) The distance Dave has to travel it S=360 m, along the y direction. Since the velocity along y is constant (4.0 m/s), this is a uniform motion, so the time taken to cross the river is given by

c) The boat takes 90 s in total to cross the river. The displacement along the y-direction, during this time, is 360 m. The displacement along the x-direction is

so, Dave's landing point is 540 m downstream.
d) If there were no current, Dave would still take 90 seconds to cross the river, because its velocity on the y-axis (4.0 m/s) does not change, so the problem would be solved exactly as done at point b).
When an earthquake strikes usually seismic waves carry the energy outward (a.) With the greatest power at the focus and as the seismic waves travel outward they become more and more weak until they disappear.<span />
Answer:
Explanation:
In the electric field pointing right , force on the electron will be towards left . Since charge is moving towards right so it is doing some work against the force . Hence its potential energy will increase. Whenever a work is done against a force , the work done is converted into potential energy in conservative field. Electric field is also a conservative field.
Answer:
The relative size of an object serves as an important monocular cue for depth perception. It works like this: If two objects are roughly the same size, the object that looks the largest will be judged as being the closest to the observer. This applies to three-dimensional scenes as well as two-dimensional images.
Explanation:
Explanation:
One common property with all halogens in group 7 is that they are all non-metals.
Fluorine, chlorine, Bromine and Iodine are classified as non-metallic elements and they have a high electronegativity.
- In chemical reactions, they are very reactive because they require just one electron to complete their octet configuration and be isoelectronic with noble gases.
The most prominent observation from halogens is that they all non-metallic in nature.