Answer:
-6.8 m/s²
Explanation:
Given:
v₀ = 30.5 m/s
v = 0 m/s
t = 4.5 s
Find: a
a = (v − v₀) / t
a = (0 m/s − 30.5 m/s) / 4.5 s
a = -6.8 m/s²
 
        
             
        
        
        
Hey there! 
The periodic table is arranged by number of protons/electrons which is the same for all isotopes of an element. <u>A different isotope will have a different number of neutrons only, which does not qualify it for a separate space on the periodic table.</u>
I hope this helps! 
 
        
             
        
        
        
Answer:
1.) h = 164.8 m
2.) U = 49.1 m/s
3.) t = 1.43 seconds 
Explanation:
1.) A soccer ball is dropped from the top of a building. It takes 5.8 seconds to fall to the ground. The height of the building is...? 
Since the soccer ball is dropped from the building, the initial velocity U will be equal to zero 
Using second equation of motion 
h = Ut + 1/2gt^2 
Substitutes the time into the formula 
h = 1/2 × 9.8 × 5.8^2
h = 164.8 m
2. The Falcon 9 launches to a height of 123 meters. What is its vertical initial velocity? 
At maximum height final velocity = 0
Using the third law of motion 
V^2 = U^2 - 2gH 
0 = U^2 - 2 × 9.8 × 123
U^2 = 2410.8
U = 49.1 m/s
3. An apple falls from rest off a 10.m m tree. How long will it take before it hits the ground?
Since the apple fall from rest, the initial velocity U will be equal to zero 
Using the second equation of motion, 
h = Ut + 1/2gt^2 
substitute all the parameters into the formula 
10 = 1/2 × 9.8 × t^2
10 = 4.9t^2 
t^2 = 10/4.9
t^2 = 2.04
t = 1.43 seconds 
 
        
             
        
        
        
Answer:
The ratio of the resistances of second coil to the first coil is the ratio of square of radius of the first coil to the square of radius of  second coil. 
And 
The ratio of the resistances of fourth coil to the third coil is the ratio of square of radius of the third coil to the square of radius of  fourth coil. 
Explanation:
The resistance of the coil is directly proportional to the length of the coil and inversely proportional to the area of coil and hence inversely proportional to the square of radius of the coil. 
So, the ratio of the resistances of second coil to the first coil is the ratio of square of radius of the first coil to the square of radius of  second coil. 
And 
The ratio of the resistances of fourth coil to the third coil is the ratio of square of radius of the third coil to the square of radius of  fourth coil.