In free fall the object with less air resistance falls with a greater acceleration

The resolving power of a microscope is proportional to the wavelength used. A resolution of 1.0 10-11 m (0.010 nm) would be requ

Anon25 [30]

Answer:

K = 13448.64eV

Explanation:

(a) In order to calculate the kinetic energy of the electrons, to "see" the atom, you take into account that the wavelength of the electrons must be of the order of the resolution required (0.010nm).

Then, you first calculate, by using the Broglies' relation, the momentum of the electron associated to a wavelength of 0.010nm:

$p=\frac{h}{\lambda}$ (1)

p: momentum of the electron

h: Planck's constant = 6.626*10^-34 Js

λ: wavelength = 0.010nm

You replace the values of the parameters in the equation (1):

$p=\frac{6.262*10^{-34}Js}{0.010*10^{-9}m}=6.262*10^{-23}kg\frac{m}{s}$

With this values of the momentum of the electron you can calculate the kinetic energy of the electron by using the following formula:

$K=\frac{p^2}{2m}$ (2)

m: mass of the electron = 9.1*10^-31 kg

$K=\frac{(6.262*10^{-23}kgm/s)^2}{2(9.1*10^{-31}kg)}=2.15*10^{-15 }J$

In electron volts you obtain:

$2.15*10^{-15}J*\frac{6.242*10^{18}eV}{1J}=13448.64eV$

The kinetic energy required for the electrons must be, at least, of 13448.64 eV

5 0

3 years ago

What happens to water when it changes to ice?

mamaluj [8]

When water changes to ice, its density decreases and its volume increases.

7 0

3 years ago

A bullet is shot vertically upward with an initial velocity of 128 ft/s. The bullet's height after t seconds is y(t) = 128t - 16

saul85 [17]

The height of the bullet when the velocity is zero is 256 ft.

<h3>Height of the bullet when the velocity is zero </h3>

The height of the bullet when the velocity is zero is determined by taking derivative of the function as shown below;

$v = \frac{dy}{dt} = 128 -32t \\\\when \ v \ is \ zero\\\\v = 0\\\\128 - 32t = 0\\\\32t = 128\\\\t = \frac{128}{32} \\\\t = 4 \ s$

The height of the bullet at this time is calculated as follows;

$y(4) = 128(4) - 16(4)^2\\\\y(4) = 256 \ ft$

Learn more about height of projectiles here: brainly.com/question/10008919

6 0

3 years ago

the jamaican bobsled team hit the brakes on their sled so that it decelerates at a uniform rate of 0.43 m/s, how long does it ta

IceJOKER [234]

<span>here's a cheap trick
it would take the same time to accelerate from rest to top speed
as it would take to decelerate from top speed to zero
so
instead of
d = Vi t + 1/2 a t^2 where Vi is positive and a is negative
we'll use
Vi = 0 and a is positive
giving
85 = 0 + 1/2 (0.43) t^2 = 0.215 t^2
t^2 = 395.345
t = 19.88s or 20. s to 2 sig figs

or we ccould find Vi from
Vf*2 = Vi^2 + 2 a d
0 = Vi^2 + 2 (0.43) 85
Vi^2 = 71.4
Vi = 8.45m/s
then
85 = 8.45 t + 1/2 (-0.43) t^2
85 = 8.45 t - 0.215 t^2
0.215 t^2 - 8.45 + 85 = 0
t = 19.65s or 20. s to 2 s.f.(minor difference arises from rounding Vi)
or another cheap trick
when a is constant
Vavg = (Vf + Vi) /2 = 8.45/2 = 4.225
and
d = Vavg t
85 = 4.225 t
t = 20.12 or 20. s to 2 s.f. (minor differences from intermidiate roundings)

anyway you choose you get 20. s</span>

4 0

3 years ago

A horizontal force pushes a 26 kg sled along a driveway for a distance of 36 m. If the coefficient of sliding friction is 0.2, w

SVETLANKA909090 [29]

Answer:1834.56 joules

Explanation:

Distance=36m

Coefficient of friction=0.2

Mass=26kg

Acceleration due to gravity=9.8m/s^2

Reaction=mass x acceleration due to gravity

Reaction=26 x 9.8

Reaction=254.8N

Coefficient of friction=frictional force ➗ reaction

0.2=frictional force ➗ 254.8

Frictional force=0.2 x 254.8

Frictional force=50.96N

work=friction force x distance

Work=50.96 x 36

Work=1834.56

Work=1834.56 joules

8 0

4 years ago