16) A wheel of moment of inertia of 5.00 kg-m2 starts from rest and accelerates under a constant torque of 3.00 N-m for 8.00 s.
2 answers:
You might be interested in
Ok so we are given the radius of 7cm and time of 5 seconds.
From the data we got we can calculate speed, frequency, perimeter and area of the semicircle.
Let's start with perimeter.
We know that perimeter of circle is so the perimeter of semicircle is
or simply
So the perimeter is equal to:
So this is the length of a curve or let's say the distance.
Now let's look at the linear speed where d is distance and t time.
We know the distance and we know the time.
So let's calculate it.
Hope this helps.
r3t40
Let be the direction the swimmer must swim relative to east. Then her velocity relative to the water is
The current has velocity vector (relative to the Earth)
The swimmer's resultant velocity (her velocity relative to the Earth) is then
We want the resultant vector to be pointing straight north, which means its horizontal component must be 0:
which is approximately 41º west of north.
As the question is about changing in frequency of a wave for an observer who is moving relative to the wave source, the concept that should come to our minds is "Doppler's effect."
Now the general formula of the Doppler's effect is:
-- (A)
Note: We do not need to worry about the signs, as everything is moving towards each other. If something/somebody were moving away, we would have the negative sign. However, in this problem it is not the issue.
Where,
g = Speed of sound = 340m/s.
= Velocity of the receiver/observer relative to the medium = ?.
= Velocity of the source with respect to medium = 0 m/s.
= Frequency emitted from source = 400 Hz.
= Observed frequency = 408Hz.
Plug-in the above values in the equation (A), you would get:
Solving above would give you,
= 6.8 m/s
The correct answer = 6.8m/s
Now the general formula of the Doppler's effect is:
Note: We do not need to worry about the signs, as everything is moving towards each other. If something/somebody were moving away, we would have the negative sign. However, in this problem it is not the issue.
Where,
g = Speed of sound = 340m/s.
Plug-in the above values in the equation (A), you would get:
Solving above would give you,
The correct answer = 6.8m/s
Answer:
The wife have to sit at 0.46 L from the middle point of the seesaw.
Explanation:
We need to make a sketch of the seesaw and the loads acting over it.
And by the studying of the Newton's law we can find the equation useful to find the distance of the mother sitting on the seesaw with respect to the center ot the pivot point.
A logical intuition will give us the idea that the mother will be on the side of her son to make the balance.
The maximum momentum with respect to the pivot point (0) will be:
Where L/2 is the half of the distance of the seesaw
Therefore the other loads ( mom + son) must be create a momentum equal to the maximum momentum.
