Answer:

Explanation:
Given that,
The instantaneous current in the circuit is giveen by :

We need to find the rms value of the current.
The general equation of current is given by :

It means, 
We know that,

So, the rms value of current is 2.12 A.
 
        
             
        
        
        
B. Aluminum is possibly correct
 
        
             
        
        
        
The final temperature of the system is 32.5°
we know,  H = mcT 
where, H = Heat content of the body 
m = Mass,
c = Specific heat 
T = Change in temperature
According to to the Principle of Calorimetry 
The net heat remains constant i.e. 
⇒ the heat given by water = heat accepted by the aluminum container.
⇒ 330 x 1 x (45 - T) = 855 x 

 x (T - 10) 
⇒ 14,850 - 330T = 183.21T  - 1832 
⇒ - 513.21 T = - 16682
or T = 32.5°
 
        
        
        
The distance travel is 69.5 meters.
<u>Explanation:</u>
Given datas are as follows
Speed = 27.8 meters / second
Time = 2.5 seconds
The formula to calculate the speed using distance and time is
Speed = Distance ÷ Time (units)
Then Distance = Speed × Time (units)
Distance = (27.8 × 2.5) meters          
Distance = 69.50 meters
Therefore the distance travelled is 69.50 meters.
 
        
             
        
        
        
Answer:
 6.4m/s
Explanation:
The total mechanical energy of the man is 1780J. 
This mechanical energy is the energy due to the motion of the body and it is a form of kinetic energy. 
  Also, mass  = 87kg 
    Kinetic energy  =  m v²
   m v²
m is the mass 
v is the velocity 
            1780  =   x 87 x v²
 x 87 x v² 
                 v²  = 40.9
                 v  = 6.4m/s