Answer:
66.98 db
Explanation:
We know that

L_T= Total signal level in db
n= number of sources
L_S= signal level from signal source.

= 66.98 db
dimensions of the bed is given as



now the volume of the bed is given as


now the mass of water in it is given as



<em>so it will contain 1581 kg mass in it</em>
Answer:
The tension in the cable when the craft was being lowered to the seafloor is 4700 N.
Explanation:
Given that,
When the craft was stationary, the tension in the cable was 6500 N.
When the craft was lowered or raised at a steady rate, the motion through the water added an 1800 N.
The drag force of 1800 N will act in the upward direction. As it was lowered or raised at a steady rate, so its acceleration is 0. As a result, net force is 0. So,
T + F = W
Here, T is tension
F = 1800 N
W = 6500 N
Tension becomes :

So, the tension in the cable when the craft was being lowered to the seafloor is 4700 N.
Answer:
The child's mass is 14.133 kg
Explanation:
From the principle of conservation of linear momentum, we have;
(m₁ + m₂) × v₁ + m₃ × v₂ = (m₁ + m₂) × v₃ - m₃ × v₄
We include the negative sign as the velocities were given as moving in the opposite directions
Since the child and the ball are at rest, we have;
v₁ = 0 m/s and v₂= 0 m/s
Hence;
0 = m₁ × v₃ - m₂ × v₄
(m₁ + m₂)× v₃ = m₃ × v₄
Where:
m₁ = Mass of the child
m₂ = Mass of the scooter = 2.4 kg
v₃ = Final velocity of the child and scooter = 0.45 m/s
m₃ = Mass of the ball = 2.4 kg
v₄ = Final velocity of the ball = 3.1 m/s
Plugging the values gives;
(m₁ + 2.4)× 0.45 = 2.4 × 3.1
(m₁ + 2.4) = 16.533
∴ m₁ + 2.4 = 16.533
m₁ = 16.533 - 2.4 = 14.133 kg
The child's mass = 14.133 kg.
Answer: a) The Answer to the question is option a) None of it.
Explanation:
The reason is because according to the law of conservation of energy Energy can neither be created nor destroyed but can be transformed from one form to the other. Therefore none of the kinetic energy was dissipated, rather it was transformed to another form of energy.