I believe the answer is potential energy if i remember correctly. 
        
                    
             
        
        
        
Answer:
The helicopter uses 35 gallons to fly for 5 hours.
Explanation:
The amount of gas that a helicopter uses for flying varies directly proportional to the number of hours spent flying.
g ∝ T
where g represents amount of gas and T time of flight.
Then,

The helicopter files 4 hours and uses 28 gallons of fuel.
Here, g₁= 28 gallons, T₁=4 hours
g₂=?, T₂=5 hours.


⇒28×5= g₂×4
⇒ g₂×4=28×5

 gallons
 gallons
The helicopter uses 35 gallons to fly for 5 hours.
 
        
             
        
        
        
Answer:
Water in dal lake is test for any heavy metals and pollutant, sewage and drainage system are also monitored for the same.
Explanation:
- Dal lake is located in Srinagar that is the state capital of Kashmir and is known for recreation and tourism purposes. The area covers about 18 km sq. and forms a part of natural wetlands.
- The lake is prone to pollution and has recently undergone restoration measures. To address the problems of eutrophication algae and large-scale microplankton have been removed from the water.
- The government of India has taken various measures to check the pollution by setting up a committee to monitor the proper use of allotted funds.
 
        
             
        
        
        
Answer:
a)  , b)
, b)  , c)
, c) 
Explanation:
a) The capacitance of two parallel plates capacitor with dielectric is given by the following expression: 

Where:
 - Dielectric constant.
 - Dielectric constant.
 - Vaccum permitivity.
 - Vaccum permitivity.
 - Plate area.
 - Plate area.
 - Distance between plates.
 - Distance between plates.
Hence, the capacitance of the system is:



b) The charge can be found by using the definition of capacitance:




c) The energy stored in the charged capacitor is:



