Answer:
<h2><em>
12.45eV</em></h2>
Explanation:
Before calculating the work function, we must know the formula for calculating the kinetic energy of an electron. The kinetic energy of an electron is the taken as the difference between incident photon energy and work function of a metal.
Mathematically, KE = hf - Ф where;
h is the Planck constant
f is the frequency = c/λ
c is the speed of light
λ is the wavelength
Ф is the work function
The formula will become KE = hc/λ - Ф. Making the work function the subject of the formula we have;
Ф = hc/λ - KE
Ф = hc/λ - 1/2mv²
Given parameters
c = 3*10⁸m/s
λ = 97*10⁻⁹m
velocity of the electron v = 3.48*10⁵m/s
h = 6.62607015 × 10⁻³⁴
m is the mass of the electron = 9.10938356 × 10⁻³¹kg
Substituting the given parameters into the formula Ф = hc/λ - 1/2mv²
Ф = 6.63 × 10⁻³⁴*3*10⁸/97*10⁻⁹ - 1/2*9.11*10⁻³¹(3.48*10⁵)²
Ф = 0.205*10⁻¹⁷ - 4.555*10⁻³¹*12.1104*10¹⁰
Ф = 0.205*10⁻¹⁷ - 55.163*10⁻²¹
Ф = 0.205*10⁻¹⁷ - 0.0055.163*10⁻¹⁷
Ф = 0.1995*10⁻¹⁷Joules
Since 1eV = 1.60218*10⁻¹⁹J
x = 0.1995*10⁻¹⁷Joules
cross multiply
x = 0.1995*10⁻¹⁷/1.60218*10⁻¹⁹
x = 0.1245*10²
x = 12.45eV
<em>Hence the work function of the metal in eV is 12.45eV</em>
Gravity is the only one helping it.
Answer:
In a third class lever, the effort is located between the load and the fulcrum. ... If the fulcrum is closer to the effort, then the load will move a greater distance. A pair of tweezers, swinging a baseball bat or using your arm to lift something are examples of third class levers.
Explanation:
Answer:
124.88 km/h
34.69 m/s
Explanation:
1633.8 km = 1633800 m
13 hours 4 minutes 58 seconds = 13 + 4/60 + 58/3600 = 13.083 hours
13 hours 4 minutes 58 seconds = 13*3600 + 4*60 + 58 = 47098 seconds
So the average speed in km/h is
1633.8 / 13.083 = 124.88 km/h
The average speed in m/s is
1633800 / 47098 = 34.69 m/s
Answer:
V = 2.8 m/s
Explanation:
It is given that,
Mass of falcon, 
Mass of dove, 
Initial velocity of falcon, 
Initial velocity of dove, 
When the falcon catches the dove, the momentum remains conserved. Using the formula for the conservation of momentum as :
V is the velocity after impact
V = 2.8 m/s
So, their velocity after the impact is 2.8 m/s. Hence, this is the required solution.
