Formula for gravitational force shows it is inversely proportional to the distance between two masses squared this is similar to the electrostatic force thay changes according to the separation squared.
The difference is that gravity is proportional to the product of the two masses. Electro static force is proportional to the product of the two charges.
Answer:
19.5°
Explanation:
The energy of the mass must be conserved. The energy is given by:
1) 
where m is the mass, v is the velocity and h is the hight of the mass.
Let the height at the lowest point of the be h=0, the energy of the mass will be:
2) 
The energy when the mass comes to a stop will be:
3) 
Setting equations 2 and 3 equal and solving for height h will give:
4) 
The angle ∅ of the string with the vertical with the mass at the highest point will be given by:
5) 
where l is the lenght of the string.
Combining equations 4 and 5 and solving for ∅:
6) 
Answer:
259.274 kW
Explanation:
Given:
Area of the lava, A = 1.00 m²
Temperature of the surrounding, T₁ = 30.0° C = 303 k
Temperature of the lava, T₂ = 1190° C = 1463 K
emissivity, e = 1
Now,
from the Stefan-Boltzmann law of radiation the rate of heat loss is given as,
u = σeA(T₂⁴ - T₁⁴)
where,
u = rate of heat loss
σ = Stefan-Boltzmann constant = 5.67 × 10⁻⁸ W/m²∙K⁴
on substituting the respective values, we get
u = 5.67 × 10⁻⁸ × 1 × 1 × (1463⁴ - 303⁴)
or
u = 259274.957 W
or
u = 259.274 kW
<span>I am pretty sure the correct answer is C.
It makes the most sense.
Please correct me if I'm wrong.</span>
