All categories

3 years ago

What can happen overnight to soil?

1 answer:

7 0

(GABS) Overnight, all of the particles settled down to the bottom , and the larger particles were on the bottom and the smaller particles were on the top. Therefore, clay was on top, hummus was in the middle, and soil was on the bottom.
Particles dissolve is an unique way

You might be interested in

Which statement about projectile motion is true?

Svetllana [295]

C. The range of a projectile increases with an increase in the angle of launch.

3 0

2 years ago

Read 2 more answers

What conversion takes place in a generator?

Andrew [12]

Answer:

B. An electric current into a magnetic field

Explanation:

The generation of electrical power requires relative motion between a magnetic field and a conductor. In a generator, mechanical energy is converted into electrical energy. The electricity produced by most generators is in the form of alternating current.

5 0

3 years ago

Read 2 more answers

The following table lists the work functions of a few common metals, measured in electron volts. Metal Φ(eV) Cesium 1.9 Potassiu

Citrus2011 [14]

A. Lithium

The equation for the photoelectric effect is:

$E=\phi + K$

where

$E=\frac{hc}{\lambda}$ is the energy of the incident light, with h being the Planck constant, c being the speed of light, and $\lambda$ being the wavelength

$\phi$ is the work function of the metal (the minimum energy needed to extract one photoelectron from the surface of the metal)

K is the maximum kinetic energy of the photoelectron

In this problem, we have

$\lambda=190 nm=1.9\cdot 10^{-7}m$ , so the energy of the incident light is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{1.9\cdot 10^{-7} m}=1.05\cdot 10^{-18}J$

Converting in electronvolts,

$E=\frac{1.05\cdot 10^{-18}J}{1.6\cdot 10^{-19} J/eV}=6.5 eV$

Since the electrons are emitted from the surface with a maximum kinetic energy of

K = 4.0 eV

The work function of this metal is

$\phi = E-K=6.5 eV-4.0 eV=2.5 eV$

So, the metal is Lithium.

B. cesium, potassium, sodium

The wavelength of green light is

$\lambda=510 nm=5.1\cdot 10^{-7} m$

So its energy is

$E=\frac{hc}{\lambda}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{5.1\cdot 10^{-7} m}=3.9\cdot 10^{-19}J$

Converting in electronvolts,

$E=\frac{3.9\cdot 10^{-19}J}{1.6\cdot 10^{-19} J/eV}=2.4 eV$

So, all the metals that have work function smaller than this value will be able to emit photoelectrons, so:

Cesium

Potassium

Sodium

C. 4.9 eV

In this case, we have

- Copper work function: $\phi = 4.5 eV$

- Maximum kinetic energy of the emitted electrons: K = 2.7 eV

So, the energy of the incident light is

$E=\phi+K=4.5 eV+2.7 eV=7.2 eV$

Then the copper is replaced with sodium, which has work function of

$\phi = 2.3 eV$

So, if the same light shine on sodium, then the maximum kinetic energy of the emitted electrons will be

$K=E-\phi = 7.2 eV-2.3 eV=4.9 eV$

7 0

3 years ago

3. Which planet, other than Earth, is confirmed to have water on it?

Nadusha1986 [10]

Mars.

Water exists as small amounts of ice on Mars and as water vapor. It is suspected that Mars used to have flowing water on it, but that there is none left now.

8 0

2 years ago

The pulley system has a mechanical advantage of 5. Determine how much input force is required to achieve 1000 N of lifting force

Katen [24]

I don’t think I need anything from my dad to get my hair fixed so I’m just bored I don’t want you guys

8 0

2 years ago