Answer:
Time period for Simple pendulum, 
Explanation:
The Simple Pendulum
Consider a small bob of mass  is tied to extensible string of length
 is tied to extensible string of length  that is fixed to rigid support. The bob is oscillating in the plane about verticle.
 that is fixed to rigid support. The bob is oscillating in the plane about verticle.
        Let  is the angle made by string with vertical  during oscillation.
 is the angle made by string with vertical  during oscillation. 
Vertical component of the force on bob,  
 
Negative sign shows that its opposing the motion of bob.
Taking  as very small angle then,
 as very small angle then, 
 
    
Let  is the displacement made by bob from its mean position ,
 is the displacement made by bob from its mean position ,
then, 
so,  ........(1)
                ........(1)
Since, pendulum is in hormonic motion,
as we know, 
where  is the constant and
 is the constant and 
 .........(2)
                   .........(2)
From equation (1) and (2)


Since, 


 
        
             
        
        
        
Answer: mass for Pyrex glass 84.21g
mass for sand 61.6g
mass for ethanol 41.32g
mass for water 62.07g
Explanation
By definition specific heat is the amount of heat required to change the temperature of 1 kg mas by 1°C
Q=mcΔT is formula for specific heat
Q is heat transfer
m is mass
ΔT is change in temperature
c   is specific heat
c of Pyrex glass= 0.75 j/g°C
c of sand = 0.84 j/g°C
c of ethanol= 2.42 j/g°C
c of water = 4.18 j/g°C
now we will make M(mass) the subject, so equation becomes 
m=Q/cΔT
for
pyrex glass T<em>f=</em>55.4°C
m=1920/(55.4-25)*0.75
m=84.21g {after cutting J(joules) and °C we are left with g(grams)}
for
sand T<em>f</em>=62.1°C
m=1920/(62.1-25)*0.84
m=61.6g {after cutting J(joules) and °C we are left with g(grams)}
for
ethanol T<em>f</em>=44.2°C
m=1920/(44.2-25)*2.42
m=41.32g  {after cutting J(joules) and °C we are left with g(grams)}
for
water T<em>f=</em>32.4°
m=1920/(32.4-25)*4.18
m=62.07g  {after cutting J(joules) and °C we are left with g(grams)}
i hope you understand the solution, thank you.
 
        
             
        
        
        
Environmental Protection Agency enforced regulations primarily aim to reduce environmental pesticide contamination.
<h3>What is a Pesticide?</h3>
This refers to a chemical which is used to control pests and examples include insecticide, nematicide etc.
Environmental Protection Agency is government owned and ensures strict enforcement of regulations to reduce environmental pesticide contamination which could lead to death of beneficial organisms.
Read more about Environmental Protection Agency here brainly.com/question/23486143
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Answer:
a) r=4.24cm d=1 cm
b) 
Explanation:
The capacitance depends only of the geometry of the capacitor so to design in this case knowing the Voltage and the electric field 


The distance must be the separation the r distance can be find also using 

But now don't know the charge these plates can hold yet so
a).
d=0.01m



b).


 
        
             
        
        
        
Answer:
The right approach is "8.1 m/s". A further explanation is provided below.
Explanation:
According to the table,
Speed of Boat
= 



Now,
⇒  
or,
⇒  
               
          
               