Answer:
V = 15m/s
Explanation:
Given the following data;
Initial velocity = 3m/s
Time = 8secs
Acceleration = 1.5m/s²
To find the final velocity, we would use the first equation of motion;
V = U + at
Substituting into the equation, we have
V = 3 + 1.5*8
V = 3 + 12
V = 15m/s
Answer: 
Explanation: In a mass-spring-damper system, the differential equation that rules the motion of the mass is: mx" + cx' + kx = 0
Using m = 4, k = 24 and c = 20, we have
4x" + 20x' + 24x = 0
Simplifying, we have
x" + 5x'+ 6x = 0
The characteristic equation of this differential is

The solutions for the quadratic equation are:
and 
Hence:
x(t) = 
x'(t) = 
To determine the constants, we have the initial conditions x(0) = 4 and
x'(0) = 2, then:


Substituing the constants:

The position function for this system is: 
Answer:

Explanation:
Assume a point sound source that emits a sound power<em> P </em>(in W) evenly in all directions of space. Let us also assume that the medium does not absorb this sound power when it passes through it. At a distance<em> d </em>from the source this power will have been evenly distributed over the surface of a sphere of radius <em>d</em>. Therefore, the acoustic intensity I at distance d will be worth:

This is the expression of the so-called<em> law of the square of distance: "the intensity is inversely proportional to the square of the distance to the source (considered punctual)".</em>
So






Answer:
Number of protons = 
Number of electrons = 
Charge on these electrons = -
Explanation:
1 atom of lead contains 82 protons and 82 electrons
1 mole =
atoms
Thus,
1 mole of lead contains
protons
Also, 1 mole of lead weighs 207.2 g
So,
207.2 g of lead contains
protons
1 kg = 1000 g
So,
1000 g or 1 kg of lead contains
protons
<u>Number of protons =
</u>
Also, for neutral atom, number of protons = number of electrons.
Thus,
<u>Number of electrons =
</u>
Also,
Charge of 1 electron = - 
Charge on these electrons = -
<u>Charge on these electrons = -
</u>