The five planets that you can see from Earth without a telescope are Mercury, Venus, Mars, Jupiter and Saturn. 
        
             
        
        
        
Answer:
I = 33.04A
Explanation:
The magnetic field at the center of a loop of wire is proportional to the current flowing through the wire and inversely proportional to the radius
So therefore we have:
20/23 = I/38.0
We then solve for I
cross multiplying we have 20 x 38 = 23 x I
I = 20 x 38/ 23
I = 33.04A
 
        
             
        
        
        
Answer:
ω = 22.36 Hz
f = 3.56 Hz
T = 0.28 s.       
Explanation:
a) The angular frequency (ω), can be calculated using the following equation:
 
  
<u>Where:</u>
<em>k: is the spring constant = F/x</em>
<em>m: is the mass of the particle = 0.500 kg</em>
<em>F: is the force applied = 7.50 N       </em>
<em>x: is the displacement = 3.00 cm = 0.03 m </em>             
 
    
Therefore, the angular frequency of the motion is 22.36 Hz.
b) To find the frequency (f) we can use the next equation:

Hence, the frequency of the motion is 3.56 Hz.
c) The period (T) is equal to:

Therefore, the period of the motion is 0.28 s.
I hope it helps you!