Ask question

Ask question

All categories

4 years ago

5

Electrons of wavelength 1.5 nm are emitted from a material when light of wavelength 350nm is incident on it. What is the work fu

nction of this material?

1 answer:

krok68 [10]4 years ago

7 0

Answer:

3.5434 eV

Explanation:

For a particle with kinetic energy E and mass m , the wavelength associated is given by the following relation,

$\lambda=\frac{h}{\sqrt{2mE} }$

E = $\frac{h^2}{2m\lambda^2}$

Putting the values we get

E = $\frac{(6.6\times(10^{-34})^2}{2\times9.1\times10^{-31\times(1.5\times10^{-9})^2}}$

=1.063 x 10⁻²¹ J

= .0066 eV.

Energy of¹light in terms of eV

= 1244 / 350 = 3.55 eV.

Work function = 3.55 - 0.0066 = 3.5434 eV.

You might be interested in

Which of the following are examples of levers?

guajiro [1.7K]

The examples of levers are seesaw, door and corkscrew

Answer: Option A, B, and C

<u>Explanation:</u>

A simple machine which is capable of rotating or moving with respect to a fixed point at the center of mass is termed as lever. Lever is made up of a rigid rod which acts as the beam or the object on which the effort can be applied based on the load and a fixed hinge like thing named as fulcrum or the center of mass.

The fulcrum will be fixed and the beam will be rotating or moving with the support of fulcrum at the center for given load or effort. So among the given options, ramp is not falling under the categories of lever as door also have a fulcrum. But the ramp is only an inclined plane without fulcrum. But the Seesaw, door and the corkscrew has both fulcrum and beam which confirms them falling in the category of lever.

5 0

4 years ago

An office heater puts out 2090 Btu (British thermal units) of energy in the form of heat per hour. Given that 1 Btu=1.055 kJ, ho

lesya692 [45]

Answer:

Total energy produced 19135.362 MJ/year

Explanation:

given details:

total energy produced = 2090 Btu per hour

1 Btu = 1.055kJ

Total energy produced per year in mega joule is = 2090*1.055 *365*24

= 19315362 KJ/year

In mega joule per year $= \frac{19315362}{1000}$

mega joule per year = 19135.362 MJ/year

5 0

3 years ago

A 1 uF parallel-plate capacitor is charged to 12 V and then disconnected from the voltage supply. The plate separation distance

nlexa [21]

Answer:

22

Explanation:

6 0

3 years ago

How much force would it would be required to stop a 950kg car traveling at 30 M/S in 1.5 seconds

gavmur [86]

Answer:

28500

Explanation:

Force equation - F = m * a

F = 950 * 30

F = 28500

7 0

3 years ago

What is the net torque on the square plate, with sides 0.2 m, from each of the three forces? F1=18 N, F2=26 N, and F3=14 N. Use

marshall27 [118]

Answer:

The net torque on the square plate is 2.72 N-m.

Explanation:

Given that,

Side = 0.2 m

Force $F_{1}=18\ N$

Force $F_{2}=26\ N$

Force $F_{3}=14\ N$

We need to calculate the torque due to force F₁

Using formula of torque

$\tau_{1}=-F_{1}d_{1}$

$\tau_{1}=-F_{1}\times\dfrac{a}{2}$

Put the value into the formula

$\tau_{1}=-18\times\dfrac{0.2}{2}$

$\tau_{1}=-1.8\ N-m$

We need to calculate the torque due to force F₂

Using formula of torque

$\tau_{2}=F_{2}d_{2}$

$\tau_{2}=F_{2}\times\dfrac{a}{2}$

Put the value into the formula

$\tau_{2}=26\times\dfrac{0.2}{2}$

$\tau_{2}=2.6\ N-m$

We need to calculate the torque due to force F₃

Using formula of torque

$\tau_{3}=F_{3}d_{3}$

$\tau_{3}=(F_{3}\sin45+F_{3}\cos45)\times\dfrac{a}{2}$

Put the value into the formula

$\tau_{3}=0.1(14\sin45+14\cos45)$

$\tau_{3}=1.92\ N-m$

We need to calculate the net torque on the square plate

$\tau=\tau_{1}+\tau_{2}+\tau_{3}$

$\tau=-1.8+2.6+1.92$

$\tau=2.72\ N-m$

Hence, The net torque on the square plate is 2.72 N-m.

3 0

3 years ago