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4 years ago

Please help im stuck

Physics

2 answers:

dlinn [17]4 years ago

6 0

Answer:

1) B

2) B

Explanation:

1) because the relative atomic mass of zinc is 29 and it has a valence electron of 2+ charge.

2) Oxygen because it is has the second highest electronegativity and has a valence electron of-2 charge.

gizmo_the_mogwai [7]4 years ago

3 0

Answer:

1.b,2.b

Explanation:

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A 300 cm rope under a tension of 120 N is set into oscillation. The mass density of the rope is 120 g/cm. What is the frequency

Vikki [24]

Answer:

Explanation:

f = $\sqrt{T/(m/L)} / 2L$

T = 120 N

L = 3.00 m

(m/L) = 120 g/cm(100 cm/m / 1000 g/kg) = 12 kg/m

(wow that's massive for a "rope")

f = $\sqrt{120/12} /(2(3))$ )

f = $\sqrt{10\\}$ /6 = 0.527 Hz

This is a completely silly exercise unless this "rope" is in space somewhere as the weight of the rope (353 N on earth) far exceeds the tension applied.

A much more reasonable linear density would be 120 g/m resulting in a frequency of √1000/6 = 5.27 Hz on a rope that weighs only 3.5 N

5 0

3 years ago

At 45 degrees s latitude, the angle of the noon sun is lowest and the length of daylight is shortest on:

Marat540 [252]

Answer;

- June 21

At 45 degrees latitude, the angle of the noon sun is lowest and the length of daylight is shortest on June 21.

Explanation;

-On June 21 you will note that the Northern Hemisphere is pitched toward the Sun. This means that the Sun's vertical ray is striking the Earth at the Tropic of Cancer (23.5 degrees N).

-Days tend to get longer in the northern hemisphere from December 21 to June 21, and then grow shorter from June 21 to December 21. The June solstice is the summer solstice in the Northern Hemisphere and the winter solstice in the Southern Hemisphere. The date varies between June 20 and June 22, depending on the year, and the local time zone.

8 0

3 years ago

A uniform electric field of magnitude 144 kV/m is directed upward in a region of space. A uniform magnetic field of magnitude 0.

snow_lady [41]

Complete Question

A uniform electric field of magnitude 144 kV/m is directed upward in a region of space. A uniform magnetic field of magnitude 0.38 T perpendicular to the electric field also exists in this region. A beam of positively charged particles travels into the region. Determine the speed of the particles at which they will not be deflected by the crossed electric and magnetic fields. (Assume the beam of particles travels perpendicularly to both fields.)

Answer:

The velocity is $v = 3.79 *10^{5} \ m/s$

Explanation:

From the question we are told that

The magnitude of the electric field is $E = 144 \ kV /m = 144*10^{3} \ V/m$

The magnetic field is $B = 0.38 \ T$

The force due to the electric field is mathematically represented as

$F_e = E * q$

and

The force due to the magnetic field is mathematically represented as

$F_b = q * v * B * sin(\theta )$

Now given that it is perpendicular , $\theta = 90$

=> $F_b = q * v * B * sin(90)$

=> $F_b = q * v * B$

Now given that it is not deflected it means that

$F_ e = F_b$

=> $q * E = q * v * B$

=> $v = \frac{E}{B }$

substituting values

$v = \frac{ 144 *10^{3}}{0.38 }$

$v = 3.79 *10^{5} \ m/s$

7 0

3 years ago

Andrea was watching her brother in the ocean and noticed that the waves were coming into the beach at a frequency of 0.777778 Hz

Stolb23 [73]

8 wave units I guess I tried it should be the answer though

3 0

4 years ago

A 40.0 turn coil of wire of radius 3.0 cm is placed between the poles of an electromagnet. The field increases from 0 to 0.75 T

nadezda [96]

Answer:

Induced emf, $V=3.76\times 10^{-4}\ V$

Explanation:

We have,

Number of turns in the coil, N = 40

Radius of coil, r = 3 cm = 0.03 m

The field increases from 0 to 0.75 T at a constant rate in a time interval of 225 s.

It is required to find the magnitude of the induced emf in the coil if the field is perpendicular to the plane of the coil. The induced emf is given by :

$\epsilon=\dfrac{d\phi}{dt}$

$\phi=NBA\cos\theta$ , is magnetic flux

$\epsilon=NA\dfrac{dB}{dt}\\\\\epsilon=\dfrac{40\times \pi (0.03)^2\times (0.75-0)}{225}\\\\\epsilon=3.76\times 10^{-4}\ V$

So, the magnitude of induced emf is $3.76\times 10^{-4}\ V$ .

7 0

3 years ago

Please help im stuck ​

Please help im stuck