So we substitute equation
[link] into Equation
[link] , and we find that
$${a}_{o}=\frac{G{m}_{e}}{{r}^{2}}$$
Since it doesn't matter what
${m}_{o}$ is, this tells us that the acceleration on a body (due to the Earth's gravity) does not depend on the mass of the body. Thus all objects experience the same gravitational acceleration. The force on different bodies will be different but the acceleration will be the same. Due to the fact that this acceleration caused by gravity is the same on all objects we label it differently, instead of using
$a$ we use
$g$ which we call the gravitational acceleration.
Comparative problems
Comparative problems involve calculation of something in terms of something else that we know. For example, if you weigh 490 N on Earth and the gravitational acceleration on Venus is 0,903 that of the gravitational acceleration on the Earth, then you would weigh 0,903 x 490 N = 442,5 N on Venus.
Principles for answering comparative problems
Write out equations and calculate all quantities for the given situation
Write out all relationships between variable from first and
second case
Write out second case
Substitute all first case variables into second case
Write second case in terms of first case
A man has a mass of 70 kg. The planet Zirgon is the same size as the Earth but has twice the mass of the Earth. What would the man weigh on Zirgon, if the gravitational acceleration on Earth is 9,8 m
$\xb7$ s
${}^{-2}$ ?
The following has been provided:
the mass of the man,
$m$
the mass of the planet Zirgon (
${m}_{Z}$ ) in terms of the mass of the Earth (
${m}_{E}$ ),
${m}_{Z}=2{m}_{E}$
the radius of the planet Zirgon (
${r}_{Z}$ ) in terms of the radius of the Earth (
${r}_{E}$ ),
${r}_{Z}={r}_{E}$
We are required to determine the man's weight on Zirgon (
${w}_{Z}$ ). We can do this by using:
$$w=mg=G\frac{{m}_{1}\xb7{m}_{2}}{{r}^{2}}$$
to calculate the weight of the man on Earth and then use this value to determine the weight of the man on Zirgon.
Write the equation for the gravitational force on Zirgon and then substitute the values for
${m}_{Z}$ and
${r}_{Z}$ , in terms of the values for the Earth.
A man has a mass of 70 kg. On the planet Beeble how much will he weigh if Beeble has mass half of that of the Earth and a radius one quarter that of the Earth. Gravitational acceleration on Earth is 9,8 m
$\xb7$ s
${}^{-2}$ .
The following has been provided:
the mass of the man on Earth,
$m$
the mass of the planet Beeble (
${m}_{B}$ ) in terms of the mass of the Earth (
${m}_{E}$ ),
${m}_{B}=\frac{1}{2}{m}_{E}$
the radius of the planet Beeble (
${r}_{B}$ ) in terms of the radius of the Earth (
${r}_{E}$ ),
${r}_{B}=\frac{1}{4}{r}_{E}$
We are required to determine the man's weight on Beeble (
${w}_{B}$ ). We can do this by using:
$$w=mg=G\frac{{m}_{1}\xb7{m}_{2}}{{r}^{2}}$$
to calculate the weight of the man on Earth and then use this value to determine the weight of the man on Beeble.
Write the equation for the gravitational force on Beeble and then substitute the values for
${m}_{B}$ and
${r}_{B}$ , in terms of the values for the Earth.
In this morden time nanotechnology used in many field .
1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc
2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc
3- Atomobile -MEMS, Coating on car etc.
and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change .
maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.