Answer:
hmax = 1/2 · v²/g
Explanation:
Hi there!
Due to the conservation of energy and since there is no dissipative force (like friction) all the kinetic energy (KE) of the ball has to be converted into gravitational potential energy (PE) when the ball comes to stop.
KE = PE
Where KE is the initial kinetic energy and PE is the final potential energy.
The kinetic energy of the ball is calculated as follows:
KE = 1/2 · m · v²
Where:
m = mass of the ball
v = velocity.
The potential energy is calculated as follows:
PE = m · g · h
Where:
m = mass of the ball.
g = acceleration due to gravity (known value: 9.81 m/s²).
h = height.
At the maximum height, the potential energy is equal to the initial kinetic energy because the energy is conserved, i.e, all the kinetic energy was converted into potential energy (there was no energy dissipation as heat because there was no friction). Then:
PE = KE
m · g · hmax = 1/2 · m · v²
Solving for hmax:
hmax = 1/2 · v² / g
This problem can be solved based on the rule of energy conservation, as the energy of the photon covers both the energy needed to overcome the binding energy as well as the energy of ejection.
The rule can be written as follows:
energy of photon = binding energy + kinetic energy of ejectection
(hc) / lambda = E + 0.5 x m x v^2 where:
h is plank's constant = 6.63 x 10^-34 m^2 kg / s
c is the speed of light = 3 x 10^8 m/sec
lambda is the wavelength = 310 nm
E is the required binding energy
m is the mass of photon = 9.11 x 10^-31 kg
v is the velocity = 3.45 x 10^5 m/s
So, as you can see, all the parameters in the equation are given except for E. Substitute to get the required E as follows:
(6.63x10^-34x3x10^8)/(310x10^-9) = E + 0.5(9.11 x 10^-31)(3.45x10^5)^2
E = 6.41 x 10^-16 joule
To get the E in ev, just divide the value in joules by 1.6 x 10^-19
E = 4.009 ev
Answer:
Thermal Power = 460W
Explanation:
From Stephan-Boltzmann Law Formula;
P = єσT⁴A
Where,
P = Radiation energy
σ = Stefan-Boltzmann Constant
T = absolute temperature in Kelvin
є = Emissivity of the material.
A=Area of the emitting body
Now, σ = 5.67 x 10^(-8)
є = 0.6
Temperature = 30°C and coverting to kelvin = 30 + 273 = 303K
Area ; since we are to consider the sides of the human body as 2m and 0.8m,thus area = 2 x 0.8 = 1.6
Thus thermal power = 0.6 x 5.67 x 10^(-8) x303⁴ x 1.6 = 458. 8W
Normally, we approximate to the nearest 10W. Thus, thermal power is approximately 460W
Answer:
Explanation:
The mass of the deuteron = mass of the proton + mass of the neutron + mass equivalent of the energy of 2.2 Mev evolved.
I amu = 931 Mev
2.2 Mev = 2.2 / 931 amu
= ( 2.2 / 931 )x 1.6726 x 10⁻²⁷
= .00395 x 10⁻²⁷
The mass of the deuteron =( 1.6726 + 1.6749 + .00395)x 10⁻²⁷ kg
= 3.35145 x 10⁻²⁷ kg
b ) Momentum of gamma ray
= h / λ ( h is plank's constant and λ is wavelength of gamma ray )
= hυ / υλ ( υ is frequency of gamma ray )
= E / c ( E is energy of photon and c is velocity o light )
= 2.2 x 10⁶ x 1.6 x 10⁻¹⁹ J / 3 x 10⁸
= 1.173 x 10⁻²¹ Kg m /s
This will be the momentum of deuteron also
Kinetic energy
= p² / 2m ( p is momentum and m is mass of deuteron )
= ( 1.173 x 10⁻²¹ )² / ( 2 x 3.35145 x 10⁻²⁷)
= 1.376 x ⁻¹⁵ J
Energy of gamma ray
= 2.2 x 10⁶ x 1.6 x 10⁻¹⁹ J
= 3.52 x 10⁻¹³ J
So kinetic energy of deuteron is smaller than energy of gamma ray photon .
Answer:
45 meters
Explanation:
20 min = 15 meters
So if 20 x 3 = 60
you have to do 3 x 15 !
- which equals to 45 <3
<u>- mark me brainlest pls . </u>
