Answer:
F = 7.68 10¹¹ N, θ = 45º
Explanation:
In this exercise we ask for the net electric force. Let's start by writing the configuration of the charges, the charges of the same sign must be on the diagonal of the cube so that the net force is directed towards the interior of the cube, see in the attached numbering and sign of the charges
The net force is
F_ {net} = F₂₁ + F₂₃ + F₂₄
bold letters indicate vectors. The easiest method to solve this exercise is by using the components of each force.
let's use trigonometry
cos 45 = F₂₄ₓ / F₂₄
sin 45 = F_{24y) / F₂₄
F₂₄ₓ = F₂₄ cos 45
F_{24y} = F₂₄ sin 45
let's do the sum on each axis
X axis
Fₓ = -F₂₁ + F₂₄ₓ
Fₓ = -F₂₁₁ + F₂₄ cos 45
Y axis
F_y = - F₂₃ + F_{24y}
F_y = -F₂₃ + F₂₄ sin 45
They indicate that the magnitude of all charges is the same, therefore
F₂₁ = F₂₃
Let's use Coulomb's law
F₂₁ = k q₁ q₂ / r₁₂²
the distance between the two charges is
r = a
F₂₁ = k q² / a²
we calculate F₂₄
F₂₄ = k q₂ q₄ / r₂₄²
the distance is
r² = a² + a²
r² = 2 a²
we substitute
F₂₄ = k q² / 2 a²
we substitute in the components of the forces
Fx = 
Fx = 
( -1 + ½ cos 45)
F_y = k \frac{q^2}{a^2} ( -1 + ½ sin 45)
We calculate
F₀ = 9 10⁹ 4.25² / 0.440²
F₀ = 8.40 10¹¹ N
Fₓ = 8.40 10¹¹ (½ 0.707 - 1)
Fₓ = -5.43 10¹¹ N
remember cos 45 = sin 45
F_y = - 5.43 10¹¹ N
We can give the resultant force in two ways
a) F = Fₓ î + F_y ^j
F = -5.43 10¹¹ (i + j) N
b) In the form of module and angle.
For the module we use the Pythagorean theorem
F = 
F = 5.43 10¹¹ √2
F = 7.68 10¹¹ N
in angle is
θ = 45º
Answer:
The temperature change of the copper is greater than the temperature change of the water.
Explanation:
deltaQ = mc(deltaT)
Where,
delta T = change in the temperature
m =mass
c = heat capacity
The temperature change in the copper is nearly 11 times the temperature change in the water.
So, the correct option is,
The temperature change of the copper is greater than the temperature change of the water.
Hope this helps!
Answer:
The deceleration is 
Explanation:
From the question we are told that
The distance of the car from the crossing is 
The speed is 
The reaction time of the engineer is 
Generally the distance covered during the reaction time is
=> 
=> 
Generally distance of the car from the crossing after the engineer reacts is
=> 
=> 
Generally from kinematic equation
Here v is the final velocity of the car which is 0 m/s
So
=>
Additionally, the coefficient of thermal expansion of the restorative material should be comparable to the coefficient of thermal expansion of the tooth structure, since a significant difference between the two could result in thermal-induced stress at the cavity wall and subsequent marginal failure.
This study's objective was to assess how thermal stress affected the marginal integrity of restorative materials with various adhesive and thermal characteristics. As an alternative to clinical trials, which are expensive and time-consuming, evaluation of restorative materials under laboratory simulations of clinical function is frequently carried out. Thermal cycling regimens, which are in vitro techniques that subject the restoration and the tooth to extremely high temperatures, are frequently used in laboratory simulations to replicate thermal stresses that naturally occur in vivo.
Learn more about Thermal Stress here-
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Dark matter may explain <span>unexpected orbital velocities of stars in galaxies.</span>
