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3 years ago

How do scientists construct models of atoms and molecules?

1 answer:

6 0

Mr. Roentgen's x-rays allowed scientists to measure the size of the atom. The x-rays were small enough to discern the atomic clouds. This was done by scattering x-rays from atoms and measuring their size just as Rutherford had done earlier by hitting atoms with other nuclei starting with alpha particles.

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During an IFR cross-country flight you picked up rime icing which you estimate is 1/2" thick on the leading edge of the wings. Y

True [87]

A. You have to manage your approach and landing at speeds higher than normal.

The ice has changed the shape of the wings, and you can't count on having the normal amounts of lift and drag if you come in at normal speeds.

6 0

4 years ago

Heat is transfered from the heating elements to the pot

Varvara68 [4.7K]

Hear is transferred from the heating elements to the Pot by Conductivity

8 0

4 years ago

When making a sound source near a reflective surface, such as making a person at a podium, the sound can reflect off of the surf

Liula [17]

Answer:

1. By removing the reflector or reflecting elements

2. By using absorbing material on the reflecting surfaces.

Explanation:

To solve problems caused by reflecting surfaces, you can remove the reflector or reflecting elements. However, sometimes it is enough to turn/move the reflecting element and change the reflections. Furthermore, using absorbing material on the reflecting surface can help reduce comb filtering as well.

In some cases, it is possible to place the sound source so close to the reflecting surface, that there is no suspension between the direct sound and the reflected sound.

5 0

4 years ago

Consider a tall building located on the Earth's equator. As the Earth rotates, a person on the top floor of the building moves f

Irina18 [472]

Answer:

$x=\frac{2h(\omega R)^{2}}{g}$

Explanation:

When the object fall from the top floor it moves with parabolic motion.

This particular case is a horizontal motion of a projectile, so the equation that relates the distance and the time in the y-axes is:

$y=y_{0}+v_{0y}-0.5gt^{2}$

Here: y is the final height, it will be 0, because the object touch the ground.

y₀ is the initial height, it will be h and v₀ in y-axis is zero, because it has a horizontal initial velocity.

So we have:

$0=h+0-0.5gt^{2}$

$h=0.5gt^{2}$ (1)

We know that the velocity at the x-axes remains constant, then we have:

$v_{0x}=\frac{x}{t}$

x is the distance from the base of the building

we can solve it for t and put on (1).

$t=\frac{x}{v_{0x}}$

$h=0.5g\left(\frac{x}{v_{0x}}\right)^{2}$

Solving it for x we will have:

$x=\frac{2hv_{0x}^{2}}{g}$

But $v_{0x}=\omega R[\tex]R is the distance from the center of the earth to the top of the building.ω is the angular speed of the earth.Finally:[tex]x=\frac{2h(\omega R)^{2}}{g}$

I hope it helps you!

4 0

4 years ago

A man and his dog are “walking” on flat Street. He is pulling on his stubborn dog with a force of 70 N Directed at a 30° angle f

Delvig [45]

Answer:

X component of force is 60.62 N.

Y component of force is 35 N.

Force of gravity on the dog is 245 N.

Magnitude of normal force is 210 N.

Explanation:

Given:

Force of pull is, $F=70\ N$

Mass of the dog is, $m=25\ kg$

Angle of inclination is, $\theta =30$ °

Acceleration due to gravity is, $g=9.8\ m/s^2$

The free body diagram of the dog is shown below.

The X and Y components of force of pull is given as:

$F_X=F\cos \theta=(70)\cos (30)=60.62\ N\\F_Y=F\sin \theta=(70)\sin(30)=35\ N$

Therefore, the X and Y components of the force are 60.62 N and 35 N respectively.

Force of gravity on the dog is the product of its mass and acceleration due to gravity. Thus,

$F_g=mg=25\times 9.8=245\ N$

Therefore, the force of gravity on the dog is 245 N.

Now, consider the motion in the vertical direction of the dog. As there is no motion in the vertical direction, the net force along the Y direction is 0. In other words, the total Upward force is equal to the total downward force.

From the free body diagram,

$N+F_Y=mg\\N=mg-F_Y\\N=245-35=210\ N$

Therefore, the normal force acting on the dog is 210 N.

6 0

4 years ago