Answer:
C) W = - 190 J
Explanation:
Notation
Wf = work done by the friction force (unknown)
Ff = force of the friction
d = distance travelled by the box = (2 pi 1.82 m) = 11.435 m
Answer:
a) 5 N b) 225 N c) 5 N
Explanation:
a) Per Coulomb's Law the repulsive force between 2 equal sign charges, is directly proportional to the product of the charges, and inversely proportional to the square of the distance between them, acting along the line that joins the charges, as follows:
F₁₂ = K Q₁ Q₂ / r₁₂²
So, if we make Q1 = Q1/5, the net effect will be to reduce the force in the same factor, i.e. F₁₂ = 25 N / 5 = 5 N
b) If we reduce the distance, from r, to r/3, as the factor is squared, the net effect will be to increase the force in a factor equal to 3² = 9.
So, we will have F₁₂ = 9. 25 N = 225 N
c) If we make Q2 = 5Q2, the force would be increased 5 times, but if at the same , we increase the distance 5 times, as the factor is squared, the net factor will be 5/25 = 1/5, so we will have:
F₁₂ = 25 N .1/5 = 5 N
Answer:
mass= 0.1993 kg
Explanation:
Using the formula c = Q / (mΔT)
I think it's potassium, but i'm not sure
Taking into account the definition of calorimetry and sensible heat, the amount of energy required is 68.8 J.
<h3>Calorimetry</h3>
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
<h3>Sensible heat</h3>
Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).
In this way, between heat and temperature there is a direct proportional relationship. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat by the mass of the body.
So, the equation that allows to calculate heat exchanges is:
Q = c× m× ΔT
where:
- Q is the heat exchanged by a body of mass m.
- c is the specific heat substance.
- ΔT is the temperature variation.
<h3>Energy required in this case</h3>
In this case, you know:
- Q= ?
- c= 0.215

- m= 20 g
- ΔT= Tfinal - Tinitial= 88 C - 72 C= 16 C
Replacing in the definition of sensible heat:
Q = 0.215
× 20 g× 16 C
Solving:
<u><em>Q=68.8 J</em></u>
Finally, the amount of energy required is 68.8 J.
Learn more about calorimetry:
<u>brainly.com/question/11586486?referrer=searchResults</u>
<u>brainly.com/question/24724338?referrer=searchResults</u>