Answer:
C. The change of internal energy of a system is the sum of work and heat spent on it.
Explanation:
The law of conservation of Energy states that energy cannot be destroyed but can only be converted or transformed from one form to another. Therefore, the sum of the initial kinetic energy and potential energy is equal to the sum of the final kinetic energy and potential energy.
Mathematically, it is given by the formula;
Ki + Ui = Kf + Uf .......equation 1
Where;
Ki and Kf are the initial and final kinetic energy respectively.
Ui and Uf are the initial and final potential energy respectively.
The law of conservation of Energy is another way to describe the law of Thermodynamics. It states that the change of internal energy of a system is the sum of work and heat spent on it.
Mathematically, it is given by the formula;
ΔU = Q − W
Where;
ΔU represents the change in internal energy of a system.
Q represents the net heat transfer in and out of the system.
W represents the sum of work (net work) done on or by the system.
The solution to the problem is as follows:
<span>Average = 80
So Sum = 80 * 5 = 400
Mode = 88, so two results are 88 (if three results were 88, then the median would be 88).
Three results are 81, 88, and 88.
That leaves 143. We could still have one 81 score, so that leaves the lowest score as 62.
Greg is in a car at the top of a roller-coaster ride. The distance, d, of the car from the ground as the car descends is determined by the equation d = 144 - 16t2, where t is the number of seconds it takes the car to travel down to each point on the ride. How many seconds will it take Greg to reach the ground?
d = 144 - 16t2
0 = 144 - 16t2
16t^2=144
t^2=9
t=3</span>
A) Pitch depends on the frequency of a sound wave. The higher the pitch, the higher the frequency and the lower the pitch, the lower the frequency. Sound waves have different pitches due to varying frequency levels.
B) Sound is created as the pen vibrates. This vibrations also interacts with the air atoms and molecules, causing them to vibrate too, therefore, creating sound waves. The reason the brain grows annoyed at this continual sound is because the brain will focus on this sound only, causing the brain to go into overdrive, creating annoyance.
C) Sound waves are travelling vibrations of particles. Space does not have any atoms or particles for the sound vibrations to interact with, therefore creating zero sound waves to travel.
Hope this helps!! :))
Answer:
a)15 N
b)12.6 N
Explanation:
Given that
Weight of block (wt)= 21 N
μs = 0.80 and μk = 0.60
We know that
Maximum value of static friction given as
Frs = μs m g = μs .wt
by putting the values
Frs= 0.8 x 21 = 16.8 N
Value of kinetic friction
Frk= μk m g = μk .wt
By putting the values
Frk= 0.6 x 21 = 12.6 N
a)
When T = 15 N
Static friction Frs= 16.8 N
Here the value of static friction is more than tension T .It means that block will not move and the value of friction force will be equal to the tension force.
Friction force = 15 N
b)
When T= 35 N
Here value of tension force is more than maximum value of static friction that is why block will move .We know that when body is in motion then kinetic friction will act on the body.so the value of friction force in this case will be 12.6 N
Friction force = 12.6 N
