Answer: 3 m.
Explanation:
Neglecting the mass of the seesaw, in order the seesaw to be balanced, the sum of the torques created by  gravity acting on both children  must be 0.
As we are asked to locate Jack at some distance from the fulcrum, we can take torques regarding the fulcrum, which is located at just in the middle of the length of the seesaw.
If we choose the counterclockwise direction as positive, we can write the torque equation as follows (assuming that Jill sits at the left end of the seesaw):
mJill* 5m -mJack* d = 0
60 kg*5 m -100 kg* d =0
Solving for d:
d = 3 m.
 
        
             
        
        
        
Answer:
Options 1 and 5 are correct
Explanation:
Magnetic field lines can never cross, the field is unique at any point in space. Magnetic field lines are continuous, forming closed loops without beginning or end. They go from the north pole to the south pole.
Magnetic field lines form closed loops but do not intersect.
Electric field lines originate at the positive charges and terminate at the negative charges. They move in a straight line and are parallel. Electric field lines neither form closed loops nor intersect.
Since, magnetic field lines form closed loops and move from North to South pole, they come out of north poles outside the magnet and into north poles inside the magnet, they also go into south poles outside the magnet and out of south poles inside the magnet. 
 
        
             
        
        
        
Answer:
2,500 Joules (J) or Newton Meter (N M)
Explanation:
Work = Force x Distance
The force in this equation is 500 Newtons. The distance (displacement) is 5 meters. Plug it into the equation above.
Work = 5m x 500n
Work = 2,500 Joules or Newton-Meters.
Therefore 2,500 Joules or Newton Meters of work is done on an object. 
 
        
             
        
        
        
Question
Rutherford tracked the motion of tiny, positively charged particles shot through a thin sheet of gold foil. Some particles  travelled in a straight line and some were deflected at different angles.
Which statement best describes what Rutherford concluded from the motion of the particles?
A) Some particles travelled through empty spaces between atoms and some particles were deflected by electrons. 
B) Some particles travelled through empty parts of the atom and some particles were deflected by electrons. 
C) Some particles travelled through empty spaces between atoms and some particles were deflected by small areas of high-density positive charge in atoms. 
D) Some particles travelled through empty parts of the atom and some particles were deflected by small areas of high-density positive charge in atoms.    
Answer:
   
The right answer is C)    
Explanation:
In the experiment described above, a piece of gold foil was hit with alpha particles, which have a positive charge. Alpha particles <em>α</em> were used because, if the nucleus was positive, then it would deflect the positive particles. The principles of physics posit that electric charges of the same orientation repel.  
So most as expected some of the alpha particles went right through meaning that the gold atoms comprised mostly empty space except the areas that were with a dense population of positive charges. This area became known as the "nucleus".  
Due to the presence of the positive charges in the nucleus, some particles had their paths bent at large angles others were deflected backwards. 
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