Take into account that in a standing wave, the frequency f of the points executing simple harmonic motion, is simply a multiple of the fundamental harmonic fo, that is:
f = n·fo
where n is an integer and fo is the first harmonic or fundamental.
fo is given by the length L of a string, in the following way:
fo = v/λ = v/(L/2) = 2v/L
becasue in the fundamental harmonic, the length of th string coincides with one hal of the wavelength of the wave.
Answer:
50 N
4.2 N
Explanation:
i) The force needed to balance the boom is 2400 N. If the weight of the counterbalance is 2350 N, then the downward force the park attendant must apply is 50 N.
ii) When the boom is resting on the end support, the normal force is:
∑τ = Iα
-W (0.50) + F (3.0) − N (6.0) = 0
-0.50 W + 3.0 F = 6.0 N
N = (-0.50 W + 3.0 F) / 6.0
N = (-0.50 × 2350 + 3.0 × 400) / 6.0
N ≈ 4.2
Answer:
90 A
Explanation:
Applying,
P = VI.............. Equation 1
Where P = Power, V = Supply voltage, I = current.
Make I the subject of the equation
I = P/V.............. Equation 2
From the question,
Assuming the Voltage of the main electric supply is 120 V
Given: P = 10.8 kW = 10800 W, V = 120 V (household voltage)
Substitute these values into equation 2
I = 10800/120
I = 90 A
