Answer:
a) attractiva, b) dF = 
, c) F = 
, d) F = -1.09 N
Explanation:
a) q1 is negative and the charge of the bar is positive therefore the force is attractive
b) For this exercise we use Coulomb's law, where we assume a card dQ₂ at a distance x
dF =
where k is a constant, Q₁ the charge at the origin, x the distance
c) To find the total force we must integrate from the beginning of the bar at x = d to the end point of the bar x = d + L
∫ dF = 
as they indicate that the load on the bar is uniformly distributed, we use the concept of linear density
λ = dQ₂ / dx
DQ₂ = λ dx
we substitute
F = 
F = k Q1 λ (
)
we evaluate the integral
F = k Q₁ λ 
F = k Q₁ λ 
we change the linear density by its value
λ = Q2 / L
F =
d) we calculate the magnitude of F
F =9 10⁹ (-4.2 10⁻⁶) 
F = -1.09 N
the sign indicates that the force is attractive
It depends on the kind of soda can
THere is a standard relationship that gives this result where the capacity of the capacitor is used:
.
We know though that Q/c=V and thus we can use the relationship:
E=Q*V/2 where we have just substituted in. If we also take into account that Q=VC, we can also get that E=V^2*C/2.
We are given the charge and the potential, so the best expression to use is the middle one.
Substituting, we get that E=1/2*8*10^(-10)*20=8*10^(-9).
The answer is B
Answer:
because it causes echoes walls are good reflectors of sound
Explanation:
pls mark brainliest ;)
<span>14.79 m/s
At the top of the loop, there's 2 opposing forces. The centripetal force that's attempting to push the roller coaster away and the gravitational attraction. These 2 forces are in opposite directions and their sum is 0.80 mg where m = mass and g = gravitational attraction. So let's calculate the amount of centripetal force we need.
0.80 = F - 1.00
1.80 = F
So we need to have a centripetal force that's 1.8 times the local gravitational attraction which is 9.8 m/s^2. So
1.8 * 9.8 m/s^2 = 17.64 m/s^2
The formula for centripetal force is
F = mv^2/r
where
F = force
m = mass
v = velocity
r = radius
We can eliminate mass from the equation since the same mass is being affected by both the centripetal force and gravity. So:
F = v^2/r
17.64 m/s^2 = v^2/12.4 m
218.736 m^2/s^2 = v^2
14.78972616 m/s = v
So the velocity at the top of the loop (rounded to 2 decimal places) is 14.79 m/s.</span>
