A good heat insulator absorbs all, or almost all, of the heat energy
from any heat that flows through it.
A good electrical insulator absorbs all, or almost all, of the energy
from any electric current that flows through it.
<span>22.5 newtons.
First, let's determine how much energy the stone had at the moment of impact. Kinetic energy is expressed as:
E = 0.5mv^2
where
E = Energy
m = mass
v = velocity
Substituting known values and solving gives:
E = 0.5 3.06 kg (7 m/s)^2
E = 1.53 kg 49 m^2/s^2
E = 74.97 kg*m^2/s^2
Now ignoring air resistance, how much energy should the rock have had?
We have a 3.06 kg moving over a distance of 10.0 m under a force of 9.8 m/s^2. So
3.06 kg * 10.0 m * 9.8 m/s^2 = 299.88 kg*m^2/s^2
So without air friction, we would have had 299.88 Joules of energy, but due to air friction we only have 74.97 Joules. The loss of energy is
299.88 J - 74.97 J = 224.91 J
So we can claim that 224.91 Joules of work was performed over a distance of 10 meters. So let's do the division.
224.91 J / 10 m
= 224.91 kg*m^2/s^2 / 10 m
= 22.491 kg*m/s^2
= 22.491 N
Rounding to 3 significant figures gives an average force of 22.5 newtons.</span>
Answer:
a) {[1.25 1.5 1.75 2.5 2.75]
[35 30 25 20 15] }
b) {[1.5 2 40]
[1.75 3 35]
[2.25 2 25]
[2.75 4 15]}
Explanation:
Matrix H: {[1.25 1.5 1.75 2 2.25 2.5 2.75]
[1 2 3 1 2 3 4]
[45 40 35 30 25 20 15]}
Its always important to get the dimensions of your matrix right. "Roman Columns" is the mental heuristic I use since a matrix is defined by its rows first and then its column such that a 2 X 5 matrix has 2 rows and 5 columns.
Next, it helps in the beginning to think of a matrix as a grid, labeling your rows with letters (A, B, C, ...) and your columns with numbers (1, 2, 3, ...).
For question a, we just want to take the elements A1, A2, A3, A6 and A7 from matrix H and make that the first row of matrix G. And then we will take the elements B3, B4, B5, B6 and B7 from matrix H as our second row in matrix G.
For question b, we will be taking columns from matrix H and making them rows in our matrix K. The second column of H looks like this:
{[1.5]
[2]
[40]}
Transposing this column will make our first row of K look like this:
{[1.5 2 40]}
Repeating for columns 3, 5 and 7 will give us the final matrix K as seen above.
Answer:
4
Explanation:
Refraction is the bending of light when it moves from one medium to another.
In the situation described:
- The average speed of light changes when it goes to another medium. The speed of light in water is less than in air.
- When velocity/speed changes, the index of refraction changes as well. Water's index is greater than in air.
- Since, speed changes, wavelength changes too.
- Only the frequency remains the same. The rates of vibration stays the same.
Correct choice is #4.
Well, I think the answer would be 4 meters because the speed is in meters per second and the frequency is 5 waves every 2 seconds.
Wavelength = Speed/Frequency
I think the frequency is 2.5 waves a second but that's not something I'm 100% sure about.
I hope this helps though.
