Which element has a -2 charge?

The circle on the left shows a magnified view of a very small portion of liquid water in a closed container. What would the magn

Alex73 [517]

Answer: WE NEED THE IMAGES TO AWNSER YOU QUESTION

Explanation:

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6 0

3 years ago

Read 2 more answers

About ________ percent of wais scores fall between 70 and 130.

stiv31 [10]

It is about 95%. The Wechsler Adult Intelligence Scale-IV is an IQ test that is given by therapists and measures worldwide scholarly working. It incorporates both verbal and nonverbal parts. The normal score for all tests and subtests is 100; therefore, a score of more than 100 is better than expected and beneath 100 is underneath normal.

5 0

4 years ago

A tennis ball is hit with a vertical speed of 10 m/s and a horizontal speed of 30 m/s. How far will the ball travel horizontally

sweet-ann [11.9K]

Answer:

D) 60 m

Explanation:

We can use the constant acceleration equation that contains displacement, initial velocity, acceleration, and time. We want to solve for the time that the ball was in the air first.

Δx = v_i * t + 1/2at²

Let's use this equation in terms of the y-direction.

Δx_y = (v_i)y * t + 1/2a_y * t²

The vertical displacement will be 0 meters since the ball will be on the floor. The initial vertical velocity is 10 m/s, the vertical acceleration is g = 10 m/s², and we are going to solve for time t.

Let's set the upwards direction to be positive and the downwards direction to be negative. We must use -g to be consistent with our other values.

Plug the known values into the equation.

0 m = 10 m/s * t + 1/2(-10 m/s²) * t²

Simplify the equation.

0 = -10t + 5t²
0 = 5t² - 10t

Factor the equation.

0 = 5t(t - 2)

Solve for t by setting both factors to 0.

5t = 0
t - 2 = 0

We get t = 0, t = 2. We must use t = 2 seconds because it is the only value for t that makes sense in the problem.

Now that we have the time that the ball was in the air, we can use the same constant acceleration equation to determine the horizontal displacement of the tennis ball. We will use this equation in terms of the x-direction:

Δx = v_i * t + 1/2at²
Δx_x = (v_i)x * t + 1/2a_x * t²

Plug the known values into the equation.

Δx_x = 30 m/s * 2 sec + 1/2(0 m/s²) * (2 sec)²

We can eliminate the right side of the equation since anything multiplied by 0 outputs 0.

Δx_x = 30 * 2
Δx_x = 60

The horizontal displacement of the ball is 60 meters. Therefore, the answer is D) 60 m.

4 0

3 years ago

The magnetic field in a plane monochromatic electromagnetic wave with wavelength λ = 598 nm, propagating in a vacuum in the z-di

Oksanka [162]

Answer:

For this given plane monochromatic electromagnetic wave with wavelength λ=598 nm, the wavenumber is $k=0,0105\ x\ 10^{-9}\ m^{-1}$ .

Explanation:

For a plane electromagnetic wave we have that the electrical and magnetic field are:

$E(r,t)=E_{0}\ cos ( wt-kr)\\\ B(r,t)=B_{0}\ cos(wt-kr)$

In this case we have the data for the magnetic field. We are told that the magnetic field in a plane electromagnetic wave with wavelength λ=598 nm, propagating in a vacuum in the z direction ( $\hat k$ ) is described by