PHYSICS
HIGH SCHOOL

B. emitted.

C. absorbed.

D. transferred.

Answer:

The key word here is "fell". Electrons don't really 'fall', but we

describe the process that way because it's like falling in gravity,

where you lose potential energy. Similarly, when an electron

transitions to a lower energy level, it has less energy, and the

energy it lost has to go somewhere. It's emitted from the atom,

in the form of a photon with a frequency that's directly related to

how much energy it's carrying.

The key word here is "fell". Electrons don't really 'fall', but we

describe the process that way because it's like falling in gravity,

where you lose potential energy. Similarly, when an electron

transitions to a lower energy level, it has less energy, and the

energy it lost has to go somewhere. It's emitted from the atom,

in the form of a photon with a frequency that's directly related to

how much energy it's carrying.

COLLEGE

A solid conducting sphere of radius 2.00 cm has a charge of 6.77 μC. A conducting spherical shell of inner radius 4.00 cm and outer radius 5.00 cm is concentric with the solid sphere and has a charge of −2.13 μC. Find the electric field at the following radii from the center of this charge configuration. (a) r = 1.00 cm (b) r = 3.00 cm (c) r = 4.50 cm (d) r = 7.00 cm

Answer:

Part a)

E = 0

Part b)

Part c)

Electric field inside the conductor is again zero

Part d)

Explanation:

Part a)

conducting sphere is of radius

R = 2 cm

so electric field inside any conductor is always zero

So electric field at r = 1 cm

E = 0

Part b)

Now at r = 3 cm

By Gauss law

Part c)

Again when we use r = 4.50 cm

then we will have

Electric field inside the conductor is again zero

Part d)

Now at r = 7 cm

again by Gauss law

COLLEGE

Why do FM stations drop out at shorter distances from their source than AM:?

Answer:

FM radios use a shorter frequency while broadcasting

Explanation:

MIDDLE SCHOOL

A car weighs 14500 N. What is the mass?

Answer:

1478.08 kg

Explanation:

Weight = mass * gravitational acceleration

14500 = mass * 9.81

mass = 1478.08 kg

Weight is depending on a gravitational acceleration . It's not depending on a mass. Mass doesnt chnage when we move object to one planet to another planet but. Gravitational acceleration is varying planet to planet .

The correct answer would be 1478.08 kg ! Hope this helps!

COLLEGE

Saturated steam coming off the turbine of a steam power plant at 40°C condenses on the outside of a 3-cm-outerdiameter, 35-m-long tube at a rate of 63 kg/h. Determine the rate of heat transfer from the steam to the cooling water flowing through the pipe. The properties of water at the saturation temperature of 40°C are hfg

Explanation:

According to the water table, the value of enthalpy of evaporation at a temperature of is 2406.0 kJ/kg.

Hence, we will calculate the rate of heat transfer by using the formula as follows.

Q =

where, m = mass

= enthalpy of evaporation

Putting the given values into the above formula as follows.

Q =

=

= 151578 kJ/h

or, =

= 42.105 kW

Thus, we can conclude that rate of heat transfer from the steam to the cooling water flowing through the pipe is 42.105 kW.

Answer:

Q = 30.07 kJ/sec

Explanation:

GIVEN DATA:

temperature of steam = 40 degree celcius

mass flow rate = 63 kg/h

from saturated water tables,

from temperature 40 °, enthalpy of evaporation value is 2406 kj/kg

rate of heat transfer (Q) can be determine by using following relation

putting all value to get Q value

Q = 45 *2406

Q = 108270 kJ/h

Q = 30.07 kJ/sec

HIGH SCHOOL

Six baseball throws are shown below. In each case the baseball is thrown at the same initial speed and from the same height h above the ground. Assume that the effects of air resistance are negligible. Rank these throws according to the speed of the baseball the instant before it hits the ground.

The six balls will reach the ground at the same time, hence the final velocity of the balls will be the same.

During a downward motion of an object, the speed of the object increases as the object moves downwards and becomes maximum before the object hits the ground.

The equation for estimating the final velocity of the six balls is given as;

If air resistance is negligible, the six balls will reach the ground at the same time, hence the final velocity of the balls will be the same.

Learn more here:brainly.com/question/9909784

Answer:

The final velocities of all the six balls will be same.

Explanation:

According to law of conservation of energy:

Gain in K.E = Loss in potential energy

½ mv^2 = mgh

Where “m” and “g” are constant. The interchange in energies will occur only with the change in velocity and height. Since, balls are thrown from the same hight with the same initial velocity so, their final velocities will also be same just before striking the ground.

MIDDLE SCHOOL

Which of the following is true of semiconductors? A. Exposing a crystal of a semiconductor to heat or light starts displacing valence electrons, which then move throughout the crystal.

B. A material is classified as a semiconductor if its resistance to the flow of electric current is too low to permit it to be called a conductor.

C. Neither free electrons nor holes are considered charge carriers in a semiconductor.

D. Gold and silver are important semiconductors

Answer:

A. Exposing a crystal of a semiconductor to heat or light starts displacing valence electrons, which then move throughout the crystal.

Explanation:

A semiconductor has several properties, the main two are:

1. Under no special treatment and polarization conditions, there can't be current flow through it due to the high resistance.

2. The semiconductor material can have special change in its structure (excess of electron or holes), to be conductive under certain polarization situations.

Answer:

B. A material is classified as a semiconductor if its resistance to the flow of electric current is too low to permit it to be called a conductor.

Explanation:

A material is classified as a semiconductor if its resistance to the flow of electric current is too low to permit it to be called a conductor is true of semiconductors.

COLLEGE

The period of a carrier wave is T=0.01 seconds. Determine the frequency and wavelength of the carrier wave. a. f=10 Hz, λ=3E8 meters b. f=100 Hz, λ=3E7 meters c. f=100 Hz, λ=3E6 meters d. f=10 Hz, λ=3E7 meters

Explanation:

It is given that,

The period of the carrier wave, T = 0.01 s

Let f and are frequency and the wavelength of the wave respectively. The relationship between the time period and the frequency is given by :

f = 100 Hz

The wavelength of a wave is given by :

So, the frequency and wavelength of the carrier wave are 100 Hz and respectively. Hence, the correct option is (c).

COLLEGE

What is the wavelength of infrared in scientific notation?

Answer:

Explanation:

Infrared radiation has wavelength in the range between 700 nm and 1 mm. Lets' convert these values into scientific notation, keeping in mind that:

Let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

The higher value is:

So, the range of wavelength of infrared radiation is:

HIGH SCHOOL

An air-filled parallel-plate capacitor has a capacitance of 1 pf. the plate separation is then doubled and a wax dielectric is inserted, completely filling the space between the plates. as a result, the capacitance becomes 2 pf. the dielectric constant of the wax is:

The equation for the capacitance of a parallel plate capacitor containing a dielectric is: C = (∈oΚA)/d, where, C is the capacitance, ∈o is the permittivity of space, Κ is the dielectric constant, A is the area of the plate, and d is the distance between the plates. Thus, when the plate separation is doubled, the capacitance is halved and since the capacitance increased from 1 pf to 2 pf, it can be concluded that the dielectric constant of the wax is equal to 4.