Equations to use: v= λ ∙ f v=d/t
2 answers:
b. 460.8 m/s
Explanation:
We have a stringth with length L = 0.90 m, and a standing wave with frequency f = 256 Hz. The equation that relates the speed of the wave with the frequency and the length of the string is
where v is the speed of the wave. Re-arranging the equation and putting in the numbers, we find:
c. 18,000 m
Explanation:
The speed of the sound wave in steel is v = 6000 m/s. The train's vibration travels for 3 seconds, so the distance covered by the sound wave during this time can be calculated using the formula
Re-arranging the equation and substituting the numbers, we can find d:
You might be interested in
Answer:
C_{y} = 4.96 and θ' = 104,5º
Explanation:
To add several vectors we can decompose each one of them, perform the sum on each axis, to find the components of the resultant and then find the module and direction.
Let's start by decomposing the two vectors.
Vector A
sin θ = / A
cos θ = Aₓ / A
A_{y} = A sin θ
Ax = A cos θ
A_{y} = 4.9 sin 31 = 2.52
Ax = 4.9 cos 31 = 4.20
Vector B
B_{y} = B sin θ
Bx = B cos θ
B_{y} = 6 sin 156 = 2.44
Bx = 6 cos 156 = -5.48
The components of the resulting vector are
X axis
Cx = Ax + B x
Cx = 4.20 -5.48
Cx = -1.28
Axis y
C_{y} = Ay + By
C_{y} = 2.52 + 2.44
C_{y} = 4.96
Let's use the Pythagorean theorem to find modulo
C = √ (Cₙ²x2 + Cy2)
C = Ra (1.28 2 + 4.96 2)
C = 5.12
We use trigonemetry to find the angle
tan θ = C_{y} / Cₓ
θ’ = tan⁻¹ (4.96 / (1.28))
θ’ = 75.5
como el valor de Cy es positivo y Cx es negativo el angulo este en el segundo cuadrante, por lo cual el angulo medido respecto de eje x positivo es
θ’ = 180 – tes
θ‘= 180 – 75,5
θ' = 104,5º