Answer:
Distance of the point where electric filed is 2.45 N/C is 1.06 m             
Explanation:
We have given charge per unit length, that is liner charge density 
Electric field E = 2.45 N/C
We have to find the distance at which electric field is 2.45 N/C
We know that electric field due to linear charge is equal to 
 , here
, here  is linear charge density and r is distance of the point where we have to find the electric field
 is linear charge density and r is distance of the point where we have to find the electric field 
So 
r = 1.06 m 
So distance of the point where electric filed is 2.45 N/C is 1.06 m 
 
        
             
        
        
        
Unlike acceleration and velocity, speed does not need to specify the direction of motion. Speed is a scalar quality.
 
        
             
        
        
        
Answer:
All of the above
Explanation:
The correct answer is option E (All of the above)
All the options are alternative source of energy.
The option given are not the traditional way (energy production from coal) of extracting energy as the loss of natural resources does not take place in these source of energy.
energy extracted from wind,  solar light , hydrogen ,etc are the source of energy  the alternative source of production of energy because do not exploit the natural resources, reduce the carbon emission and energy produced by them is clean energy.
 
        
             
        
        
        
We can calculate the density of the balloon as follows:

Therefore, the balloon will fall
Since the density of air is about 0.00123 g/cm^3 , the balloon is much more dense than the surrounding air. As a result, the balloon weighs more than the air that it displaces so the balloon will fall.
 
        
             
        
        
        
Answer:They may cause motion to change
Explanation:They may cause motion; they may also slow, stop, or change the direction of motion of an object that is already moving. Since force cause changes in the speed or direction of an object, we can say that forces cause changes in velocity. Remember that acceleration is a change in velocity.