Answer:
2.13 h
Explanation:
Simple harmonic motion is:
x = A sin(2π/T t + φ) + B
where A is the amplitude, T is the period, φ is the phase shift, and B is the midline.
This can also be written in terms of cosine:
x = A cos(2π/T t + φ) + B
Here, A = d/2, T = 12.8, φ = 0, and B = d/2. I'll use cosine so that the highest level is at t=0.
x = d/2 cos(2π/12.8 t) + d/2
When x = d - 0.250 d = 0.750 d:
0.750 d = d/2 cos(2π/12.8 t) + d/2
0.250 d = d/2 cos(2π/12.8 t)
0.500 = cos(2π/12.8 t)
π/3 = 2π/12.8 t
12.8/6 = t
t = 2.13
It takes 2.13 hours to fall 0.250 d from the highest level.
Answer:
See the answers below
Explanation:
This problem can be solved by means of the law of conservation of energy, which tells us that the energy between two points is conserved, that is, remains the same.
That is to say, we have two points, the point A where it starts to move and reaches the point B that is 1.5 [m] high, where it stops.
The key to solving this problem is to identify the types of energies at each point. At point A we have kinetic energy and potential energy where the block moves at speed 3 [m/s] at a height of 4 [m]. Whereas at Point B we only have potential energy, since the body is at a height of 1.5 [m], relative to the ground.
a)
Since between the displacement between points A and B there is a friction force, this friction force decreases the final energy in B, in this way the energy or work of the friction will have a negative sign.
Now replacing in the above equation.
b)
We must use the same equation, but this time eliminating the Working term due to friction.
As we can see without friction the block can reach a higher height
Answer:
Explanation:
Total weight
My weight+weight of belongings
660+1100=1760N.
a. Work done by the elevator to travel a total height of 15.2m
Using newton law of motion
ΣF = ma
There are only two forces acting upward, the weight and the reaction by the elevator
Also note it is moving at constant velocity then, a=0
N - W=0
Then, N=W
N=1760N
So, workdone is given as
Wordone, =force × distance
Work done=1760×15.2
W=26,752J
W=26.752KJ
b. Work done on me alone is still need to go through the same process but will remove the weight of the belonging
Therefore,
Weight now = 660N
And using the same equation of motion
ΣF = ma
Comstant velocity, a=0
N - W=0
N=W
N=660N
Then, workdone
W=F×d
W=660×15.2
W=10,032J
W=10.032KJ
Answer:
The current density is
The drift velocity is
Explanation:
From the question we are told that
The nominal diameter of the wire is
The current carried by the wire is
The power rating of the lamp is
The density of electron is
The current density is mathematically represented as
Where A is the area which is mathematically evaluated as
Substituting values
So
The drift velocity is mathematically represented as
Where e is the charge on one electron which has a value
So