1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
EleoNora [17]
3 years ago
6

Which of the following is an example of a physical change?

Physics
1 answer:
Stels [109]3 years ago
7 0

Answer:

1 question is- I believe 4. Melting Question 2 is Density

Explanation:

THOUGHT ABOUT IT!!!

You might be interested in
Water is a compound.<br> O A. True<br> B. False
puteri [66]
True because , a compound forms when two or more atoms form a chemical bond and the chemical formula for water is H2O which means each molecule of water consists of one oxygen atom
7 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
Which of the following examples illustrates static friction in action?
lilavasa [31]
I think its d. but im not sure
3 0
3 years ago
Read 2 more answers
Write any two features of capital​
amid [387]
Washington DC and new Mexico
6 0
3 years ago
Read 2 more answers
What are the parts of an atom
Ivenika [448]
Number three

They contain protons (positive), neutrons (negative), electrons (neutral) and all are in a nucleus which is part of an atom
7 0
3 years ago
Read 2 more answers
Other questions:
  • A tiger travels 3m/s^2 for 4.1s,what was its initial speed if it's final speed was 55k/h?
    15·1 answer
  • Suppose a rocket ship in deep space moves with constant acceleration equal to 9.80 m/s2, which gives the illusion of normal grav
    14·1 answer
  • A 5.0-kg block of wood is placed on a 2.0-kg aluminum frying pan. How much heat is required to raise the temperature of both the
    13·1 answer
  • Cars A and B are racing each other along the same straight road in the following manner:
    10·1 answer
  • IN a physics lab, a student discovers that the magnitude of the magnetic field at a certain distance from a long wire is 4.0μT.
    10·1 answer
  • Which of the following statements about this experiment is FALSE? Before each trial one should reshape the bob into something li
    9·1 answer
  • With the water trap being used, all the possible sources of error would be eliminated.
    11·1 answer
  • If a permanent magnet picks up a steel paper clip, the paper clip also
    7·2 answers
  • What is the period, in seconds, that corresponds to each of
    15·1 answer
  • A 21.0 kg uniform beam is attached to a wall with a hi.nge while its far end is supported by a cable such that the beam is horiz
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!