Answer:
E=252J
Explanation:
The total mechanical energy of an object or system is given by:
E mech=K+U
Where K is the kinetic energy of the object and U is the potential energy of the object. The carriage, sitting motionless at the top of the hill, has only potential energy in the form of gravitational potential energy.
Gravitational potential energy is given by:
Ug=mgh
Where m is the mass of the object, g is the gravitational acceleration constant, and h is the height of the object above some specific reference point, in this case the ground 21 m below.
The weight of a stationary object at the surface of the earth is equal to the force of gravity acting on the object.
W=→Fg=mg
We are given that the carriage weighs 12 N, therefore mg=12N.
Ug=12N⋅21m
⇒Ug=252Nm=252J
Hope it helped, God bless you!
 
        
             
        
        
        
<span>When a red giang complete helium fusion and collapses, it becomes a white dwarf. The correct option is C. White dwarf are very dense stars that are usually the size of a planet. It is a stellar core reminant which mainly made up of electron degenerated matters; its mass is comparable to that of the sun while its volume is comparable to that of the earth. </span>
        
                    
             
        
        
        
It'll be my pleasure to analyze the circuit, describe my analysis in detail,
and give you a clear, precise, and accurate answer.
As soon as you let me see the circuit diagram, with values marked on
all of its components and power sources.
        
             
        
        
        
Answer:
 X₃₁ = 0.58 m  and  X₃₂ = -1.38 m
Explanation:
For this exercise we use Newton's second law where the force is the Coulomb force
         F₁₃ - F₂₃ = 0
         F₁₃ = F₂₃
Since all charges are of the same sign, forces are repulsive
         F₁₃ = k q₁ q₃ / r₁₃²
         F₂₃ = k q₂ q₃ / r₂₃²
Let's find the distances
          r₁₃ = x₃- 0
          r₂₃ = 2 –x₃
We substitute
       k q q / x₃² = k 4q q / (2-x₃)²
       q² (2 - x₃)² = 4 q² x₃²
         4- 4x₃ + x₃² = 4 x₃²
         5x₃² + 4 x₃ - 4 = 0
We solve the quadratic equation
         x₃ = [-4 ±√(16 - 4 5 (-4)) ] / 2  5
         x₃ = [-4 ± 9.80] 10
        X₃₁ = 0.58 m
        X₃₂ = -1.38 m
For this two distance it is given that the two forces are equal
 
        
             
        
        
        
We will first convert lb to grams and in³ to milliliters. 
350 lb : 2.205 = 158.75733 kg = 158,757.33 grams
1.3 · 10^4 in³ = 13,000 in³ = 13,000 · 0.016387064 = 213.031 liters 
213.031 liters · 1,000 = 213,031 milliliters
Density = m / V = 158,753.33 g / 213,031 ml = 0.7452 g/ ml
Answer: A block of material will float.