Answer:
2.58 m/s
Explanation:
We can use the following equation of motion to find out the constant acceleration of the block:
where v = 3.8 m/s is the final velocity after it has traveled 7.4 m, is the initial velocity of the block when it starts from rest, , and is the distance traveled.
We can use the same motion equation to calculate block speed at the end of 3.4m track
Answer:
A) If you halve the wavelength, the electromagnetic radiation energy will double.
B) The energy of the electromagnetic radiation will halve if you halve the wavenumber.
C) When the frequency of the light is doubled, its energy will double.
Explanation:
The function for the light frequency is given as
The energy supplied to each electron is doubled by halving the wavelength, nearly doubling its kinetic energy by two after it is free from the metal. It is important to remember that for a given period of time, the number of electrons ejected will remain constant.
Cheers
Answer:
Explanation:
We are given that
Diameter of wire=d=4.12 mm
Radius of wire=
Current=I=
Drift velocity=
We have to find the density of free electrons in the metal
We know that
Density of electron=
Using the formula
Density of free electrons=
By using Area of wire=
Density of free electrons=
We can find the momentum of the rock by using De Broglie's relationship:
where
p is the momentum
h is the Planck constant
is the De Broglie's wavelength
By using
, we find
The momentum of the rock is
where
is the mass and v is its velocity. Rearranging the equation, we find the speed of the rock:
Answer:
U₂ = 20 J
KE₂ = 40 J
v= 12.64 m/s
Explanation:
Given that
H= 12 m
m = 0.5 kg
h= 4 m
The potential energy at position 1
U₁ = m g H
U₁ = 0.5 x 10 x 12 ( take g= 10 m/s²)
U₁ = 60 J
The potential energy at position 2
U₂ = m g h
U ₂= 0.5 x 10 x 4 ( take g= 10 m/s²)
U₂ = 20 J
The kinetic energy at position 1
KE= 0
The kinetic energy at position 2
KE= 1/2 m V²
From energy conservation
U₁+KE₁=U₂+KE₂
By putting the values
60 - 20 = KE₂
KE₂ = 40 J
lets take final velocity is v m/s
KE₂= 1/2 m v²
By putting the values
40 = 1/2 x 0.5 x v²
160 = v²
v= 12.64 m/s