According to given condition there is no height(m) given from roof of building to the ground, there height given 18 m at a point above the ground.                         So, h=18m  ,                mass=3kg     ,         g=9.8m/s2                                                                      P.E=mgh                                                                                                                P.E=(3)(9.8)(18)                                                                                                      P.E=529J
                                      
        
             
        
        
        
Answer:
a) The car was moving at a speed of 
b) The negative sign of  denotes that the observer is coming towards the police car which is the source of the sound.
 denotes that the observer is coming towards the police car which is the source of the sound.
c) 
Explanation:
Given:
- original frequency of the source,  
- speed of the source,  
- velocity of the obstacle car be,  
- speed of sound,  
- observed frequency,  
<u>Using the equation from the Doppler's effect:</u>



a)
The car was moving at a speed of 
b) 
The negative sign of  denotes that the observer is coming towards the police car which is the source of the sound.
 denotes that the observer is coming towards the police car which is the source of the sound.
c)
Now when, 
Then, 
Using the Doppler's eq.:


 
        
             
        
        
        
Answer:
Explanation:
the same amount of time in both halves of the circle
 
        
             
        
        
        
I am not entirely sure but i believe the answer is C scupture
        
                    
             
        
        
        
(a) The net flux through the coil is zero.
In fact, the magnetic field generated by the wire forms concentric circles around the wire. The wire is placed along the diameter of the coil, so we can imagine as it divides the  coil into two emisphere. Therefore, the magnetic field of the wire is perpendicular to the plane of the coil, but the direction of the field is opposite in the two emispheres. Since the two emispheres have same area, then the magnetic fluxes in the two emispheres are equal but opposite in sign, and so they cancel out when summing them together to find the net flux.
(b) If the wire passes through the center of the coil but it is perpendicular to the plane of the wire, the net flux through the coil is still zero.
In fact, the magnetic field generated by the wire forms concentric lines around the wire, so it is parallel to the plane of the coil. But the flux is equal to

where 

 is the angle between the direction of the magnetic field and the perpendicular to the plane of the coil, so in this case 

 and so the cosine is zero, therefore the net flux is zero.