Black holes is exists
Black holes is highly gravitional wave field in space
<h2>
a) Equivalent resistance is 143 Ω</h2><h2>
b) Potential difference is 71.5 V</h2>
Explanation:
When resistors are connected in series, effective resistance is given by

Here
R₁ = 21Ω
R₂ = 58Ω
R₃ = 64Ω
a) 
Equivalent resistance is 143 Ω
b) We know
Potential difference = Current x Resistance
V = IR
I = 0.5 A
R = 143Ω
Substituting
V = 0.5 x 143 = 71.5 V
Potential difference is 71.5 V
Protons, neutrons, and electrons<span> are the three main subatomic particles found in an atom. Protons have a</span>positive<span> (+) </span>charge<span>. An easy way to remember this is to remember that both proton and </span>positive<span> start with the</span>letter<span> "</span>P<span>." Neutrons have no electrical </span>charge<span>.</span>
Answer:
The value is 
Explanation:
From the question we are told that
The mass of the car is
The period of the circular motion is 
The radius is 
Generally the frequency of the circular motion is

=> 
=> 
The sentences are invalid and unsound.
<h3><u>Explanation</u>:</h3>
The fire is defined as the vigorous oxidation of a substance. Now oxidation can occur in presence of any oxidising agent. Like magnesium in presence of nitrogen in high temperature with a dazzling brownish flame to produce magnesium nitride. So fire can be produced in absence of oxygen.
Oxygen is present everywhere in world. So production of a whole room without oxygen is very tough to produce and costly process. So its very unsound.