As the frequency of the ac voltage across an inductor approaches zero, the inductive reactance of that coil Group of answer choices

Answer:

D. The person's force on the box is as strong as the force of the box on the person, but the frictional force on the person is forward and large while the backward frictional force on the box is small.

Explanation:

When a bag is pulled, then it involves a person’s force on the box meaning there is an opposite force which is equal to the force of the box on the person.

When the box is pulled, there is a forward frictional force on the person which is big when compared to the backward frictional force which is small. This positive difference is responsible for the movement of the box.

Answer:

we approach a maximum or minimum the values ​​of the ordinate are closer and closer and when passing this point the values ​​change their trend

Explanation:

The reason for this process occurs because as we approach a maximum or minimum the values ​​of the ordinate are closer and closer and when passing this point the values ​​change their trend if they were rising, they begin to fall and if they were falling they begin to rise. Therefore the maximum point is a point of inflection of the curve since its trend changes.

Another way of looking at this process is that mathematically the point where there is a maximum or a minimum corresponds to the point where the first derivative is equal to zero, this is the slope of the line is horizontal, so the points before after correspond to values ​​with slope of different sign.

Answer:3) variable affinities (stickiness) for something it is running past. Physical ... -measurement number (significant digits) unit (such as inches) -Significant ... Mass 1 oz. 28.25 g. Relations Between English and Metric Units Mass 1 dram. 1.772 g ... -graduated cylinder has an error of about 1% (± 0.1 mL in 10 mL). -Volumetric

Explanation:

Answer:

1. 28.25 mL, three significant digits.

2. 54.074 mL, three significant digits

3. 600.006 km, four significant digits

4. 1356 kg + 4.2 kg + 19.891 kg

Explanation:

Answer:

They should be connected in parallel

Explanation:

Because In Parallel circuit, voltage across all lamps are same and current will flow independent each other such that a malfunction of one will nor affect the rest unlike in series connection

Answer:

An example of operational definition of the term weight of an object, operationalized to a degree, would be the following: "weight is the numbers that appear when that object is placed on a weighing scale"

Answer:

Constructive interference

Explanation:

Because the path difference between them is zero owing to the fact that they are in phase

Answer:

The rebound speed of the mass 2m is v/2

Explanation:

I will designate the two masses as body A and body B.

mass of body A = m

mass of body B = 2m

velocity of body A = v

velocity of body B = -v    since they both move in opposite direction

final speed of mass A = 2v

final speed of body B = ?

The equation of conservation of momentum for this system is

mv - 2mv = -2mv + x

where x is the final momentum of the mass B

x = mv - 2mv + 2mv

x = mv

to get the speed, we divide the momentum by the mass of mass B

x/2m = v = mv/2m

speed of mass B = v/2

Answer:

2.7%

Explanation:

Given:

Uncertainty of the speedometer (u)= 2.5km/h

Speed measured at that uncertainty (v) = 92km/h

Percent uncertainty (p) is given as the ratio of the uncertainty to the speed measured then multiplied by 100%. i.e

p = [tex]\frac{u}{v} * 100[/tex]%

p = [tex]\frac{2.5}{92} * 100[/tex]%

p = 2.7%

Therefore, the percent uncertainty is 2.7%

Complete Question

Two spherical shells have a common center. A -1.6 x 10-6 C charge is spread uniformly over the inner shell, which has a radius of 0.030 m. A +5.1 x 10-6 C charge is spread uniformly over the outer shell, which has a radius of 0.15 m.What are the magnitude and direction of the electric field at a distance 43.5 mm from the center of the shells.

Answer:

The magnitude is  [tex]E = 7.6021*10^{6} \N/C[/tex]

The direction is radially inward toward the center

Explanation:

From the question we are told that

   The charge on the inner shell is  [tex]q_i = -1.6*10^{-6} \ C[/tex]

    The  radius of the inner shell is  [tex]c_1 = 0.030 \ m[/tex]

   The  charge on the outer shell is  [tex]q_o = 5.1*10^{-6}\ C[/tex]

     The  radius of the outer shell is  [tex]c_2 = 0.15\ m[/tex]

   The distance considered is  [tex]r = 43.5 \ mm = 0.0435 \ m[/tex]

Generally the electric field at the position considered is mathematically represented as

          [tex]E = \frac{Q_c }{4\pi r^2 \epsilon_o }[/tex]

Here  [tex]Q_c[/tex] is the charge  which is enclosed by the distance considered which in this case is the charge on the inner shell

  So  [tex]Q_c =q_i = -1.6*10^{-6} \ C[/tex]

Hence

          [tex]E = \frac{-1.6 *10^{-6} }{4* 3.142 *0.0435^2* 8.85*10^{-12} }[/tex]

 =>      [tex]E = -7.6021*10^{6} \N/C[/tex]

The negative sign is show that the direction of the field is radially inward toward the center

Answer:

A) 2 possible frequencies of second propellar = 424 rpm or 724 rpm

B) Correct frequency is f2 = 724 rpm

C) Reason is stated in explanation

Explanation:

A) We are given;

Frequency of first propeller; f1 = 574 rpm

Beat frequency; f_beat = 2.5 Hz = 2.5 × 60 rpm = 150 rpm

Now, formula for the beat frequency is;

f_beat = |f1 - f2|

Now, |f1 - f2| means it is inside an absolute value.

Thus, it means,

f1 - f2 = 150 or f2 - f1 = 150

Thus;

574 - f2 = 150

Or f2 - 574 = 150

So,f2 = 574 - 150 = 424 rpm or f2 = 574 + 150 = 724 rpm

2 possible frequencies of second propellar = 424 rpm or 724 rpm

B) Now, if we increase the speed of the second propellar slightly, it means that f2 will increase as well.

Now, from the 2 possible values of f2 gotten, we can see that for f1 - f2 = 150, when we increase f2, the beat frequency will reduce while for f2 - f1 = 150, when we increase f2, the beat frequency will increase.

Thus, it's the frequency of f2 gotten in f2 - f1 = 150 that is the correct answer.

Thus, when we increase the speed of the second propellar slightly, it means that;

f2 = 724 rpm

C) Answer in part B is correct because as we increase the speed of the second propellar, the frequency will also increase and the value of f2 that corresponds with an increase in speed is 724 rpm.

Answer:

8×10⁻¹⁷ N

Explanation:

from the question, Electric force is given as

F = QV/r.............. Equation 1

Where F = Electric Force,  Q = Charge, V = Electric potential, r = distance.

Given: Q = 8×10⁻¹⁹ C, V = 5 kV = 5000 V, r = 2 cm = 0.02 m.

Substitute into equation 1

F = 8×10⁻¹⁹(5000)(0.02)

F = 8×10⁻¹⁷ N

Hence the electric force on the dust particle is  8×10⁻¹⁷ N

Answer:

The final speed of small metal sphere is 12.6 m/s.

Explanation:

Given that,

Distance = 0.4 m

Suppose, A small metal sphere, carrying a net charge q₁ = −2μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q₂ = −8μC and mass 1.50g, is projected toward q₁. When the two spheres are 0.800m apart, q₂ is moving toward q₁ with speed 20m/s.

We need to calculate the final speed of small metal sphere

Using conservation of energy

[tex]\dfrac{1}{2}mv_{1}^2+\dfrac{kq_{1}q_{2}}{r_{1}}=\dfrac{1}{2}mv_{2}^2+\dfrac{kq_{1}q_{2}}{r_{2}}[/tex]

[tex]\dfrac{1}{2}m(v_{1}^2-v_{2}^2)=kq_{1}q_{2}(\dfrac{1}{r_{2}}-\dfrac{1}{r_{1}})[/tex]

Put the value into the formula

[tex]\dfrac{1}{2}\times1.5\times10^{-3}(20^2-v_{2}^2)=9\times10^{9}\times(-2)\times10^{-6}\times(-8)\times10^{-6}(\dfrac{1}{0.4}-\dfrac{1}{0.8})[/tex]

[tex]400-v_{2}^2=240[/tex]

[tex]-v_{2}^2=240-400[/tex]

[tex]v_{2}=\sqrt{160}\ m/s[/tex]

[tex]v_{2}=12.6\ m/s[/tex]

Hence, The final speed of small metal sphere is 12.6 m/s.

The answer is B

Explanation:

Every action has an equal reaction. If you punch a wall, the wall is going to exert the wall with exert the same amount of force back towards your hand, causing your hand to hurt.

Answer:

a.  According to Newton's Third Law, the force you put into the wall with your punch causes the wall to put the same force back onto your hand.

Explanation:

I got it correct.

Answer:

The number of photons of light produced by the laser in 1 hour is

1 Photon / hour

Explanation:

Number of photons of light produced is given by

[tex]Number of photons = \frac{Power}{Energy}[/tex]

From the question,

Power = 5 mW (milliwatts) = 5 × 10⁻³ W

Since 1 Watt = 1 Js⁻¹

Then, 5 × 10⁻³ W = 5 × 10⁻³ Js⁻¹

For the Energy,

As given from the question

Energy=(Power)x(time)

Time = 1 hour = (1 × 60 × 60) s = 3600 s

∴ Energy = 5 × 10⁻³ Js⁻¹ x 1 x 3600s

Energy =18.0 J

Now for the Number of photons produced,

[tex]Number of photons = \frac{Power}{Energy}[/tex]

Power = 5 × 10⁻³ Js⁻¹ = 0.005 Js⁻¹

[tex]Number of photons = \frac{0.005}{18}[/tex]

Number of photons = 2.78 × 10⁻⁴ Photons / sec

This is the number of photons produced in 1 second.

For the number of photons produced in 1 hour, we will multiply the result by 3600

(NOTE: 1 sec = [tex]\frac{1}{3600}[/tex] hour)

Number of photons = 2.78 × 10⁻⁴ Photons / sec

= 2.78 × 10⁻⁴ × 3600 Photons / hour

= 1.0008 Photons / hour

≅ 1 Photon / hour

Hence, the number of photons of light produced by the laser in 1 hour is

1 Photon / hour

Answer:

Lift, weight, thrust and drag.

Answer:

According to Newton's first law of motion (inertia), an object at rest will remain at rest, or an object in motion will continue in motion at the same speed and in the same direction, until an outside force acts on it. For an aircraft to taxi or fly, a force must be applied to it. It would remain at rest without an outside force. Once the aircraft is moving, another force must act on it to bring it to a stop. It would continue in motion without an outside force. This willingness of an object to remain at rest or to continue in motion is referred to as inertia.

Newton's Second Law of Motion

The second law of motion (force) states that if a object moving with uniform speed is acted upon by an external force, the change of motion (acceleration) will be directly proportional to the amount of force and inversely proportional to the mass of the object being moved. The motion will take place in the direction in which the force acts. Simply stated, this means that an object being pushed by 10 pounds of force will travel faster than it would if it were pushed by 5 pounds of force. A heavier object will accelerate more slowly than a lighter object when an equal force is applied.

Newton's Third Law of Motion

The third law of motion (action and reaction) states that for every action (force) there is an equal and opposite reaction (force). This law can be demonstrated with a balloon. If you inflate a balloon with air and release it without securing the neck, as the air is expelled the balloon moves in the opposite direction of the air rushing out of it.

Answer:

Irms =226A

Explanation:

The current is high because the total impedance is relatively low. Actually, plugging such a circuit into a 120-V outlet would most likely burn out the circuit elements

Answer:

they are describing their displacement since displacement is nothing but distance along with the direction of motion

Answer:

Yes, lava is a liquid, that cools into rock, which is a solid.

Answer:

Average speed is 5 m/s

Explanation:

The initial speed = 0 m/s (since the runner starts from rest)

Final speed = 10 m/s

time interval = 2 sec

average speed = ?

The speed is assumed to change at a constant rate

Average speed = (final speed + initial speed)/2

==> (10 + 0)/2 = 10/2 = 5 m/s

Answer:

force applied by red = 50 N

force applied by blue = - 63 N (since it is in the opposite direction)

net force = force by red + force by blue

net force = 50 + (- 63)

net force = - 13 N  

Answer:

The magnetic field at the center of the loop is 2.51 × 10⁻³ T

Explanation:

The magnetic field at the center of a circular loop is given by

B = μ₀I/2r

Where B is the magnetic field strength in Teslas (T)

μ₀ is the permeability of free space

μ₀ = 4π ×10⁻⁷ N/A²

I is the current in Amperes (A)

and r is the radius of the loop in meters (m)

From the question,

r = 1.0 cm

Convert this to meter (m)

1.0 cm = 1.0 × 10⁻² m = 0.01 m

∴ r = 0.01 m

I = 40 A

Hence, the magnetic field at the center of the loop is

B = μ₀I/2r

B = (4π ×10⁻⁷ × 40) / (2 × 0.01)

B = 5.0265 × 10⁻⁵ / 0.02

B =  2.51 × 10⁻³ T

Hence, the magnetic field at the center of the loop is 2.51 × 10⁻³ T

Answer:

B) less than 700 N

Explanation:

Given;

normal weight of the person, W = 700 N

An elevator moving upward but slowing down at a steady rate, shows that upward force is less than downward force, thus, the reading on the scale will be  less than 700 N.

Also, from Newton's second law

R - mg = ma

where;

R is the reading on the scale

mg is the weight of the person = W = 700 N

a is negative acceleration upward = -a

R - mg = -ma

R = mg - ma

Thus, If this person is standing on a bathroom scale inside the elevator, the scale will read less than 700 N.

B)  less than 700 N.

Answer:

16∠45° Ω

Explanation:

Applying,

Z = V/I................... Equation 1

Where Z = Impedance, V = Voltage output, I = current input.

Given: V = 120cos(10t+75°), = 120∠75°,  I = 7.5cos(10t+30) = 7.5∠30°

Substitute these values into equation 1

Z = 120cos(10t+75°)/7.5cos(10t+30)

Z = 120∠75°/ 7.5∠30°

Z = 16∠(75°-30)

Z = 16∠45° Ω

Hence the impedance of the linear network is 16∠45° Ω

Answer:

(a) 2.75 fm

(b) 2.89 fm

(c) 4.70 fm

(d) 7.12 fm

Explanation:

For a given element, the radius r of its nuclei is given by;

r = r₀[tex]A^{(1/3)}[/tex]

Where;

A = Atomic mass of the element

r₀ = 1.2 x 10⁻¹⁵m = 1.2fm

Now let's solve for the given elements

(a) ¹²₆C

Carbon element => This has an atomic mass number of 12

Therefore its radius is given by;

r = 1.2  x [tex]12^{1/3}[/tex]

r = 1.2 x 2.29

r = 2.75 fm

(b) ¹⁴₇N

Nitrogen element => This has an atomic mass number of 14

Therefore its radius is given by;

r = 1.2  x [tex]14^{1/3}[/tex]

r = 1.2 x 2.41

r = 2.89 fm

(c) ⁶⁰₂₇Co

Cobalt element => This has an atomic mass number of 60

Therefore its radius is given by;

r = 1.2  x [tex]60^{1/3}[/tex]

r = 1.2 x 3.92

r = 4.70 fm

(d) ²⁰⁸₈₂Pb

Lead element => This has an atomic mass number of 208

Therefore its radius is given by;

r = 1.2  x [tex]208^{1/3}[/tex]

r = 1.2 x 5.93

r = 7.12 fm

Answer:

TRICARE for Life (TFL), a program for Medicare-eligible military retirees and their dependents, acts as a supplement to Medicare.

Explanation:

Answer:

Corkscrew, bicycle, scissors

Explanation:

they are made from many simple machine's

Answer:

compound meachiun include bicycles, cars, scissors, and fising rods with reels.

Complete question:

Currents in dc transmission lines can be 100 A or higher. Some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. For a line that has current 150 A and a height of 6.0 m above the ground, what magnetic field does the line produce at ground level?

Answer:

The magnetic field the line produces at ground level is 5 x 10⁻⁶ T.

Explanation:

Given;

current in the dc transmission line, I = 150 A

height above ground level, R = 6 m

The transmission line will be treated as current in a long straight wire.

Thus, the magnetic field produced at the ground level is given as magnetic field in a long straight conductor.

[tex]B = \frac{\mu_o I}{2\pi R}[/tex]

where;

μ₀ is permeability of free space = 4π x 10⁻⁷ T.m/A

[tex]B = \frac{4\pi*10^{-7} * 150}{2\pi * 6}\\\\B = 5*10^{-6} \ T[/tex]

Therefore, the magnetic field the line produces at ground level is 5 x 10⁻⁶ T.