Answer:
Explanation:
a = F/m = 7500/2000 = 3.75 m/s²
v² = u² + 2as
s = (v² - u²) / 2a
s = (0² - 45²) / (2(-3.75))
s = 270 m
Answer:

Explanation:
The resistance of a conductor is directly proportional to its length and is inversely proportional to its cross-sectional area, this dependence is given by:

is the material's resistance, L is the legth and A is the cross-sectional area.
For the first and second coils, we have:

For the third and fourth coils, we have:

Answer:
Star A is brighter than Star B by a factor of 2754.22
Explanation:
Lets assume,
the magnitude of star A = m₁ = 1
the magnitude of star B = m₂ = 9.6
the apparent brightness of star A and star B are b₁ and b₂ respectively
Then, relation between the difference of magnitudes and apparent brightness of two stars are related as give below: 
The current magnitude scale followed was formalized by Sir Norman Pogson in 1856. On this scale a magnitude 1 star is 2.512 times brighter than magnitude 2 star. A magnitude 2 star is 2.512 time brighter than a magnitude 3 star. That means a magnitude 1 star is (2.512x2.512) brighter than magnitude 3 bright star.
We need to find the factor by which star A is brighter than star B. Using the equation given above,



Thus,

It means star A is 2754.22 time brighter than Star B.
<span>(a) E = ½ Q²/C, so ..
(b) E(max) = ½Li² (i=current), so .</span>
T<u>he direction of motion</u> of the person relative to the water is <u>16.7° north of east.</u>
Why?
We can solve the problem by applying the Pitagorean Theorem, where the first speed (to the north) and the second speed (to the east) corresponds to two legs of the right triangle formed with them. (north and east directions are perpendicular each other)
We can calculate the angle that give the direction using the following formula:

Now, substituting the given information we have:


Hence, we have that <u>the direction of motion</u> of the person relative to the water is 16.7° north of east.
Have a nice day!