Answer:90N
Explanation:
Mass=30kg
Centripetal acceleration=3m/s^2
centripetal force=mass x centripetal acceleration 
Centripetal force=30 x 3
Centripetal force =90
Centripetal force =90N
 
        
             
        
        
        
Work can be defined as the energy transferred from a body to its sorroundings, the energy spent to move a body, or the energy you need to alter a charged particle, so no energy, no work; thus, the statement is true.
        
             
        
        
        
Answer:

Explanation:
If we assume that the Earth is a spherical conductor, according to  Gauss's Law, the electric field is given by:

Here k is the Coulomb constant, the excess charge on the Earth's surface and r its radius. Solving for q:

 
        
             
        
        
        
the wavelength is to be 56.67 cm and I know that i should be applying the double slit equation for destructive interference. 
 
        
             
        
        
        
By using Lami's theorem formula, the tension in the supporting wires is 48.6 Newtons
TENSION
- Tension is also a force having Newton as S.I unit.
- The tension in the wire will be the same.
This question can be solved by using either vector diagram or by using  Lami's theorem. 
The sum of two given angles  = 42 + 42 = 84 degrees
The third angle = 180 - 84 = 96 degrees.
Below is the Lami's theorem formula

Where 
 = 42 + 90 = 132 degrees
 = 42 + 90 = 132 degrees
Y = 96 degrees
W = 65 N
By using the formula, we have

T/sin 132 = 65/sin96
Cross multiply
T = 0.743 x 65.57
T = 48.56 N
Therefore, the tension in the supporting wires is 48.6 Newtons approximately.
Learn more about Tension here: brainly.com/question/24994188