2. Which one of the following calculations could be used to find the
1 answer:
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Answer:
Distance traveled will be 5.6307 m
Explanation:
Time t = 3 sec
We have given force F = 25 N
We know that force is given by F = ma
So ma = 25 -----------eqn 1
Weight is given by W = 196 N
We know that weight is given by W = mg
So mg = 196 -----------------eqn 2
From equation 1 and equation 2
Initial velocity is given as 0 so u = 0 m/sec
From second equation of motion
Answer:
k = 11,564 N / m, w = 6.06 rad / s
Explanation:
In this exercise we have a horizontal bar and a vertical spring not stretched, the bar is released, which due to the force of gravity begins to descend, in the position of Tea = 46º it is in equilibrium;
let's apply the equilibrium condition at this point
Axis y
W_{y} - Fr = 0
Fr = k y
let's use trigonometry for the weight, we assume that the angle is measured with respect to the horizontal
sin 46 = / W
W_{y} = W sin 46
we substitute
mg sin 46 = k y
k = mg / y sin 46
If the length of the bar is L
sin 46 = y / L
y = L sin46
we substitute
k = mg / L sin 46 sin 46
k = mg / L
for an explicit calculation the length of the bar must be known, for example L = 1 m
k = 1.18 9.8 / 1
k = 11,564 N / m
With this value we look for the angular velocity for the point tea = 30º
let's use the conservation of mechanical energy
starting point, higher
Em₀ = U = mgy
end point. Point at 30º
= K -Ke = ½ I w² - ½ k y²
em₀ = Em_{f}
mgy = ½ I w² - ½ k y²
w = √ (mgy + ½ ky²) 2 / I
the height by 30º
sin 30 = y / L
y = L sin 30
y = 0.5 m
the moment of inertia of a bar that rotates at one end is
I = ⅓ mL 2
I = ½ 1.18 12
I = 0.3933 kg m²
let's calculate
w = Ra (1.18 9.8 0.5 + ½ 11,564 0.5 2) 2 / 0.3933)
w = 6.06 rad / s
Answer:
a) In the new transformer there are 42 turns in the secondary per turn in the primary, while in the old transformer there were 32 turns per turn in the primary.
b) The new output is 86% of the old output
c) The losses in the new line are 74% the losses in the old line.
Explanation:
a) To relate the turns of primary and secondary to the ratio of voltage we have this expression:
In the old transformer the ratio of voltages was:
In the new transformer the ratio of voltages is:
In the new transformer there are 42 turns in the secondary per turn in the primary, while in the old transformer there were 32 turns per turn in the primary.
b) The new current ratio is
If the old current output was 425 kV, the ratio of current was:
Then, the ratio of the new output over the old output is:
The new output is 86% of the old output (smaller output currents lower the losses on the transmission line).
c) The power loss is expressed as:
Then, the ratio of losses is (R is constant for both power losses):
The losses in the new line are 74% the losses in the old line.