Describe how the properties of sound waves change as they spread out in a spherical pattern.

What is the dot product of a= -2i - 5j and b=i -4j

Dafna1 [17]

I.i = j.j = 1
i.j = j.i = 0

(-2i - 5j)(i -4j)
= (-2i).i + (-2i).(-4j) + (-5j).i + (-5j).(-4j)
= -2 + 0 + 0 + 20 = 18

7 0

3 years ago

Suppose two children push horizontally, but in exactly opposite directions, on a third child in a sled. The first child exerts a

anyanavicka [17]

Answer:

Please, read the anser below

Explanation:

1. In order to calculate the acceleration of the children you use the Newton second law for the summation of the implied forces:

$F_2-F_1-F_f=Ma$ (1)

Where is has been used that the motion is in the direction of the applied force by the second child

F2: force of the second child = 92N

F1: force of the first child = 79N

Ff: friction force = 5.5N

M: mass of the third child = 24kg

a: acceleration of the third child = ?

You solve the equation (1) for a, and you replace the values of the other parameters:

$a=\frac{F_2-F_1.F_f}{M}=\frac{96N-79N-5.5N}{24kg}=0.48\frac{m}{s^2}$

The acceleration is 0.48m/s^2

2. The system of interest is the same as before, the acceleration calculated is about the motion of the third child.

3. An image with the diagram forces is attached below.

4. If the friction would be 150N, the acceleration would be zero, because the friction force is higher than the higher force between children, which is 92N.

Then, the acceleration is zero

3 0

3 years ago

What never change despite what planet you go to

laiz [17]

Your mass will never change despite if you go to Jupiter, Uranus, Mars, Earth, or any planet.

7 0

3 years ago

Two forces, F⃗ 1F→1F_1_vec and F⃗ 2F→2F_2_vec, act at a point. F⃗ 1F→1F_1_vec has a magnitude of 9.20 NN and is directed at an a

BARSIC [14]

Answer:

The x component of the resultant force is -7.27N.

Explanation:

To obtain the x component of the resultant force, first we have to know the x components of the other forces. To do this, we just have to do some trigonometry:

$|F_{1x}|=|F_1|\cos\theta_1=9.20N\cos62.0\°=4.31N \\|F_{2x}|=|F_2|\cos\theta_2=5.00N\cos53.6\°=2.96N$

Since both vectors are in the left side of the y-axis, they have a negative x component. So:

$F_{1x}=-4.31N;\\F_{2x}=-2.96N$

Finally, we sum both components to obtain the component of the resultant force:

$F_{Rx}=-4.31N-2.96N=-7.27N$

In words, the x component of the resultant force is -7.27N.

6 0

3 years ago

Football helmets are made with padding that helps reduce head injuries when a player collides with an object. Which bestexplains

Vlad1618 [11]

football hemets have pads that are filled with air and thick foam so when they are hit the foam asorbs the hit and the air keeps the hard outer shell of the helmet from hiting the players head

3 0

2 years ago

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