Answer:
ΔS total ≥ 0 (ΔS total = 0 if the process is carried out reversibly in the surroundings)
Explanation:
Assuming that the entropy change in the aluminium bar is due to heat exchange with the surroundings ( the lake) , then the entropy change of the aluminium bar is, according to the second law of thermodynamics, :
ΔS al ≥ ∫dQ/T
if the heat transfer is carried out reversibly
ΔS al =∫dQ/T
in the surroundings
ΔS surr ≥ -∫dQ/T = -ΔS al → ΔS surr ≥ -ΔS al = - (-1238 J/K) = 1238 J/K
the total entropy change will be
ΔS total = ΔS al + ΔS surr
ΔS total ≥ ΔS al + (-ΔS al) =
ΔS total ≥ 0
the total entropy change will be ΔS total = 0 if the process is carried out reversibly in the surroundings
Ionic is where the bonding of elements attract opposites
Answer:
Frequency of the wave is 3.8 hertz.
Explanation:
It is given that, the sinusoidal wave has following wave equation as :
![y(x,t)=(2.5\ m)sin[(3\ m^{-1})x-(24\ s^{-1})t+\pi/2]](https://tex.z-dn.net/?f=y%28x%2Ct%29%3D%282.5%5C%20m%29sin%5B%283%5C%20m%5E%7B-1%7D%29x-%2824%5C%20s%5E%7B-1%7D%29t%2B%5Cpi%2F2%5D)
The general equation for the sinusoidal wave is :
Where
A is the amplitude
k is the constant
is the angular frequency
is the phase difference
Since, 
or
f = 3.8 Hz
So, the frequency of the wave is 3.8 hertz. Hence, this is the required solution.
Answer:
F = 800N
the magnitude of the average force exerted on the wall by the ball is 800N
Explanation:
Applying the impulse-momentum equation;
Impulse = change in momentum
Ft = m∆v
F = (m∆v)/t
Where;
F = force
t = time
m = mass
∆v = v2 - v1 = change in velocity
Given;
m = 0.80 kg
t = 0.050 s
The ball strikes the wall horizontally with a speed of 25 m/s, and it bounces back with this same speed.
v2 = 25 m/s
v1 = -25 m/s
∆v = v2 - v1 = 25 - (-25) m/s = 25 +25 = 50 m/s
Substituting the values;
F = (m∆v)/t
F = (0.80×50)/0.05
F = 800N
the magnitude of the average force exerted on the wall by the ball is 800N
Answer: 
Explanation:
According to <u>Coulomb's Law:</u>
<em>"The electrostatic force 
between two point charges 
and 
is proportional to the product of the charges and inversely proportional to the square of the distance 
that separates them, and has the direction of the line that joins them".</em>
<em />
Mathematically this law is written as:
Where:
is the electrostatic force
is the Coulomb's constant
and 
are the electric charges
is the separation distance between the charges
Solving:
