Answer:
a)      K = 2/3 π G m ρ R₁³ / R₂
,  b) U = - G m M / r
Explanation:
The law of universal gravitation is
      F = G m M / r²
Part A
Let's use Newton's second law
      F = m a
The acceleration is centripetal
      a = v² / R₂
      
       G m M / R₂² = m v² / R₂
       v² = G M / R₂
They give us the density of the planet
     ρ = M / V
     V = 4/3 π R₁³
     M =   ρ V
     M =   ρ 4/3 π R₁³
     v² = 4/3 π G  ρ R₁³ / R₂
     K = ½ m v²
     K = ½ m (4/3 π G ρ R₁³ / R₂)
     K = 2/3 π G m ρ R₁³ / R₂
Part B
Potential energy and strength are related
      F = - dU / dr
      ∫ dU = - ∫ F. dr
The force was directed towards the center and the vector r outwards therefore there is an angle of 180º between the two cos 180 = -1
     U- U₀ = G m M ∫ dr / r²
     U - U₀ = G m M (- r⁻¹)
We evaluate for
     U - U₀ = -G m M (1 /  -  1 /
 -  1 / )
)
They indicate that for ri = ∞     U₀ = 0
     U = - G m M / r
 
        
             
        
        
        
The electrons making the shock come from the women's body.
<h3>What is Electric shock ?</h3>
When a high voltage current flows through the body, electrical shock results. When someone unintentionally touches an electrical source, this typically occurs. Treatment for both internal and exterior burns may be necessary as part of the aftercare.
The nervous system may be impacted by a shock.
The tissue that makes up nerves presents extremely minimal resistance to the flow of an electric charge. Electric shocks that impact nerves can cause pain, tingling, numbness, weakness, or trouble moving a limb. These effects might disappear with time or remain for good.
How to Prevent from Electrical Shocks –
- Keep the Appliances Away from Moisture and Water.
- Never Connect or Disconnect Under Load. 
- Be Careful with Capacitors. 
- Use Insulated Tools. 
- Turn Off the Power. 
- Check for Improper or Faulty Wiring. 
- Fix Extension Cord Problems.
to learn more about electric shock go to - brainly.com/question/8822505
#SPJ4
 
        
             
        
        
        
Answer:
Constructive Interference
Explanation:
Constructive Interference occurs when two waves superimpose and make bigger amplitudes. 
In constructive interference, the crests of one wave fall on the crests of second wave and the amplitudes add up. The amplitude of the resultant wave is equal to sum of the amplitude of the individual waves. Similarly, the trough of first wave falls on the trough of other wave and they superimpose to create the trough of the resultant wave. 
For Example, In the attachment, two waves A and B superimpose and demonstrate Constructive interference to create the wave C.
 
        
             
        
        
        
Answer:
The angular speed of the reel is 11.33 rad/s
Explanation:
Given
The fisherman takes t = 8.4 s to wind distance x = 2.9 m into a circle radius of r = 3 cm = 0.03 m
Than the tangencial speed equals the change in the distance to the time
v =  =
 = 
Knowing the tangencial velocity is proportional to the radius r and the angular velocity
v = r*w
w = 
 
 
 
        
             
        
        
        
Answer:
1.Gravity is an invisible force that pulls objects toward each other
2.The suns gravity pulls the planet towards the sun which changes the straight line of direction into a curve
That keeps the planet moving in an orbit around the sun
hope it helped:)