Answer:
The intensity of sound (I) = 3.16 x 10⁻⁶ W/m²
Explanation:
We have expression for sound intensity level (SIL),
Here we need to find the intensity of sound (I).
Substituting
L = 67 dB and I₀ = 10⁻¹² W/m² in the equation
The intensity of sound (I) = 3.16 x 10⁻⁶ W/m²
Answer:
6.88 mA
Explanation:
Given:
Resistance, R = 594 Ω
Capacitance = 1.3 μF
emf, V = 6.53 V
Time, t = 1 time constant
Now,
The initial current, I₀ = 
or
I₀ = 
or
I₀ = 0.0109 A
also,
I = ![I_0[1-e^{-\frac{t}{\tau}}]](https://tex.z-dn.net/?f=I_0%5B1-e%5E%7B-%5Cfrac%7Bt%7D%7B%5Ctau%7D%7D%5D)
here,
τ = time constant
e = 2.717
on substituting the respective values, we get
I = ![0.0109[1-e^{-\frac{\tau}{\tau}}]](https://tex.z-dn.net/?f=0.0109%5B1-e%5E%7B-%5Cfrac%7B%5Ctau%7D%7B%5Ctau%7D%7D%5D)
or
I = ![0.0109[1-2.717^{-1}]](https://tex.z-dn.net/?f=0.0109%5B1-2.717%5E%7B-1%7D%5D)
or
I = 0.00688 A
or
I = 6.88 mA
<h3>
Answer:</h3>
49 N
<h3>
Explanation:</h3>
<u>We are given;</u>
- Mass of the brick as 3 kg
- The coefficient of friction as 0.6
We are required to determine the force that must be applied by the woman so the brick does not fall.
- We need to importantly note that;
- For the brick not to fall the, the force due to gravity is equal to the friction force acting on the brick.
- That is; Friction force = Mg
But; Friction force = μ F
Therefore;
μ F = mg
0.6 F = 3 × 9.8
0.6 F = 29.4
F = 49 N
Therefore, she must use a force of 49 N
Answer:
525 Bq
Explanation:
The decay rate is directly proportional to the amount of radioisotope, so we can use the half-life equation:
A = A₀ (½)^(t / T)
A is the final amount
A₀ is the initial amount,
t is the time,
T is the half life
A = (8400 Bq) (½)^(18.0 min / 4.50 min)
A = (8400 Bq) (½)^4
A = (8400 Bq) (1/16)
A = 525 Bq
Answer:
The answer is below
Explanation:
The length of the rope is equal to the radius of the circle formed by the complete rotation of the rope. Therefore the radius = 1.50 m.
a) The distance covered by the rope when completing one rotation is the same as the perimeter of the circle. Hence:
Distance covered in one rotation = 2π * radius = 2π * 1.5 = 3π meters
The velocity of the ball = Distance / time = 3π meters / 3.4 seconds = 2.77 m/s
b) The initial velocity (u) is 0 m/s, the final velocity is 2.77 m/s during time (t) = 3.4 s. Hence acceleration (a):
v = u + at
2.77 = 3.4a
a = 0.82 m/s²
c) Force on ball = mass * acceleration = 4 * 0.82 = 3.28 N
