Answer:
The charge on the ball bearing 4.507 × 10^-8 C
Explanation:
From Coulomb's law
F = kq1q2/r²
make q2 the subject
q2 = Fr²/kq1
q2 = (1.8×10^-2 × 0.026²) ÷ (9×10^9 × 30×10^-9)
q2 = 4.507 × 10^-8 C
Answer:
0.0072 m³/s
Explanation:
Using Bernoulli's law
P₁ + 1/2ρv₁² = P₂ + 1/2ρv₂ since the pipe is horizontal
1/2ρv₂² - 1/2ρv₁² = P₁ - P₂
flow rate is constant
A₁v₁ = A₂v₂
A₁ = πr₁² = π (0.06/2)² = 0.0028278 m²
A₂ = πr₂² = π (0.0225)² = 0.00159 m²
v₁ = (A₂ / A₁)v₂
v₁ = (0.00159 m²/ 0.0028278 m²) v₂ = 0.562 v₂
substitute v₁ into the Bernoulli's equation
1/2ρv₂² - 1/2ρv₁² = P₁ - P₂
500 ( 1 - 0.3161 ) v₂² = (31.0 - 24 ) × 10³ Pa
341.924 v₂² = 7000
v₂² = 20.472
v₂ = √ 20.472 = 4.525 m/s
volume follow rate = 0.00159 m² × 4.525 m/s = 0.0072 m³/s
Answer: 3.84dB
Explanation:
Since person A is talking 1.2dB louder than B, we will have
A = 1.2B... (1)
Similarly, person C is talking 3.2 dB louder than person A, we have
C = 3.2A... (2)
From equation 1, B = A/1.2... (3)
To get the ratio of the sound intensity of person C to the sound intensity of person B, we will divide equation 2 by 3 to give
C/B = 3.2A/{A/1.2}
C/B = 3.2A×1.2/A
C/B = 3.2×1.2
C/B = 3.84dB
Answer:
it look the same just to tell you
