Answer:Reducing mass i.e. water
Explanation:
Frequency For given mass in glass is given by

where k =stiffness of the glass
m=mass of water in glass
from the above expression we can see that if mass is inversely Proportional to frequency
thus reducing mass we can increase frequency
Answer:
a. I = 30 A
b. E = 1080000 J = 1080 KJ
c. ΔT = 12.86°C
d. Cost = $ 4.32
Explanation:
a.
The current in the coil is given by Ohm's Law:

where,
I = current = ?
V = Voltage = 120 V
R = Resistance = 4 Ω
Therefore,

<u>I = 30 A</u>
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b.
The energy can be calculated as:

<u>E = 1080000 J = 1080 KJ</u>
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c.
For the increase in the temperature of water:

where,
m = mass of water = 20 kg
C = specific heat of water = 4.2 KJ/kg.°C
Therefore,

<u>ΔT = 12.86°C</u>
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d.
First, we will calculate the total energy consumed:

Now, for the cost:

<u>Cost = $ 4.32</u>
Imagine a right triangle where the legs represent the horizontal and vertical lengths of the string and the hypotenuse represents the length of the string.
Let us assign some values:
x = horizontal length in feet
50 = vertical length in feet
L = length of the string in feet
Because we are modeling these quantities with a right triangle, we can use the Pythagorean theorem to relate them with the following equation:
L² = x² + 50²
We want to find an equation for the change of L over time, so first differentiate both sides with respect to time t then solve for dL/dt:
2L(dL/dt) = 2x(dx/dt)
dL/dt = (x/L)(dx/dt)
First let's solve for x at the moment in time described in the problem using the Pythagorean theorem:
L² = x² + 50²
Given values:
L = 100ft
Plug in and solve for x:
100² = x² + 50²
x = 86.6ft
Now let's find dL/dt. Given values:
x = 86.6ft, L = 100ft, dx/dt = 4ft/sec
Plug in and solve for dL/dt:
dL/dt = (86.6/100)(4)
dL/dt = 3.46ft/sec
Answer:
45 kg is the mass of a table that weights 441 newton.