Answer:
40 V
Explanation:
I will assume that the resistors are
100 and 3900 and 1000 OHMS <=====(NOT W)
In series , the resistances add together 100 + 3900 + 1000 = 5000 ohms total
V = IR
I = V / R so the total current will be 200 v / 5000 ohms = .04 amps
this is the current through all of the resistors
so for the 1000 ohm resistor V = IR .04 (1000) = 40 V
Answer:
354 m/s
Explanation:
For the second overtune (Third harmonic) of an open pipe,
λ = 2L/3................................ Equation 1
Where L = Length of the open pipe, λ = Wave length.
Given: L = 1.75 m.
Substitute into equation 1
λ = 2(1.75)/3
λ = 1.17 m.
From the question,
V = λf.......................... Equation 2
V = speed of sound in the room, f = frequency
Given: f = 303 Hz.
Substitute into equation 2
V = 1.17(303)
V = 353.5
V ≈ 354 m/s
Hence the right answer is 354 m/s
Answer:
the moment of inertia with the arms extended is Io and when the arms are lowered the moment
I₀/I > 1 ⇒ w > w₀
Explanation:
The angular momentum is conserved if the external torques in the system are zero, this is achieved because the friction with the ice is very small,
L₀ = L_f
I₀ w₀ = I w
w = w₀
where we see that the angular velocity changes according to the relation of the angular moments, if we approximate the body as a cylinder with two point charges, weight of the arms
I₀ = I_cylinder + 2 m r²
where r is the distance from the center of mass of the arms to the axis of rotation, the moment of inertia of the cylinder does not change, therefore changing the distance of the arms changes the moment of inertia.
If we say that the moment of inertia with the arms extended is Io and when the arms are lowered the moment will be
I <I₀
I₀/I > 1 ⇒ w > w₀
therefore the angular velocity (rotations) must increase
in this way the skater can adjust his spin speed to the musician.
The same braking force does work on these objects to slow them down. The work done is equal to their change in kinetic energy:
FΔx = 0.5mv²
F = force, Δx = distance traveled, m = mass, v = speed
Isolate Δx:
Δx = 0.5mv²/F
Calculate Δx for each object.
Object 1: m = 4.0kg, v = 2.0m/s
Δx = 0.5(4.0)(2.0)²/F = 8/F
Object 2: m = 1.0kg, v = 4.0m/s
Δx = 0.5(1.0)(4.0)²/F = 8/F
The two objects travel the same distance before stopping.