Answer:
R₁ = 50.77 Ω
Explanation:
Since, we know that:
Electric Power = P = VI
but from Ohm's Law:
V = IR
(or) I = V/R
Therefore,
P = V²/R
(OR) R = V²/P
where,
V = Battery Voltage
R = Resistance of combination
FOR SERIES COMBINATION:
R = Rs = (57 V)²/48 W
Rs = 67.69 Ω
but, we know that:
Rs = R₁ + R₂
R₁ + R₂ = 67.69 Ω 
R₁ = 67.69 Ω - R₂  __________ eqn (1) 
FOR PARALLEL COMBINATION:
R = Rp = (57 V)²/256 W
Rp = 12.69 Ω
but, we know that:
Rp = (R₁R₂)/(R₁ + R₂) = 12.69 Ω
using eqn (1) and value of R₁ + R₂, we get
Rp = 12.69  = R₂(67.69 - R₂)/67.69 
859.08 = 67.69 R₂ - R₂²
R₂² - 67.69 R₂ + 859.08 = 0
Solving this quadratic equation we get the answers:
Either, R₂ = 50.76 Ω
Either, R₂ = 16.92 Ω 
Since, it is stated in the question that R₁ > R₂. Therefore, we choose the second value. So,
<u>R₂ = 16.92 Ω</u>
using this value in eqn (1), we get:
R₁ = 67.69 Ω - 16.92 Ω
<u>R₁ = 50.77 Ω</u>
 
        
             
        
        
        
3. Millions of years ago, the Earth was not divided into 7 continents. It was only a very large land mass, the scientists named that one land mass “Pangaea”
4. If the tectonic plates are disturbed, they can cause mass earthquakes and tsunamis.
5. The ring of fire is a massive collection of volcanoes under the pacific ocean. They all form the shape of a ring, hence the name.
SORRY, I COULDNT ANSWER THE FIRST TWO QUESTIONS.
        
                    
             
        
        
        
Answer:
2,38kg
Explanation:
Mass in function of time can be found by the formula:  , where
, where  is the initial mass, t is the time and k is a constant.
 is the initial mass, t is the time and k is a constant.
Given that a sample decay 1% per day, that means that after first day you have 99% of mass. 
 , but
, but  , so we have
, so we have  , then
, then 
Now using k found we must to find  .
.

 
        
             
        
        
        
Answer:
6.1 km
Explanation:
Given that a plane travels 4.0 km at an angle of 25◦ to the ground, then changes direction and travels 10 km at an angle of 16◦ to the ground. What is the magnitude of the plane's total displacement? Answer in units of km
The magnitude of the total displacement D can be calculated by using cosine formula 
Ø = 25 - 16 = 9 degree 
D^2 = 4^2 + 10^2 - 2 × 4 × 10 × cos 9
D^2 = 16 + 100 - 80cos9
D^2 = 116 - 79.02
D = sqrt( 36.98)
D = 6.1 m
Therefore, the magnitude of the plane's total displacement is 6.1 km
 
        
             
        
        
        
E. i - Energy (w) = Power x Time
Energy = 40 x 3600
= 14,400 joules 
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