Note: <em>The question states the time to go upstream is a number of times (not explicitly written) the time to go downstream. We'll assume a general number N</em>
Answer:
Explanation:
<u>Relative Speed</u>
If a boat is going upstream against the water current, the true speed of motion is 
, being 
the speed of the boat and 
the speed of the water. If the boat is going downstream, the true speed becomes 
.
The question states the time to go upstream is a number of times N (not explicitly written) the time to go downstream. The speed of an object is computed as
Where x is the distance traveled and t the time taken for that. The time can be computed by
If 
is the time for the upstream travel and 
is the time for the downstream travel, then
Siince the same distance x= 10 miles is traveled in both cases:
Simplifying and rearrangling
Operating
Solving for
If N=3
We can use the required value of N to compute the speed of the boat as explained
Answer:
shielding of electrons
Explanation:
The addition of electrons shells results in the shielding of electrons away from the nucleus, most importantly the nuclear pull resulting from the charge.
- The nucleus pulls electrons to itself due to the net positive charge on it.
- As more electronic shell is added, the effect of the pull weakens outward.
- The inner shell experiences the nuclear pull more than the outer shell electrons.
The effect is responsible for a wide range of properties of elements.
Resistance = voltage / current
Resistance = 63 / 4
Resistance = 15.75 ohms
