Answer: 
Explanation:
The kinetic energy of an electron
is given by the following equation:
(1)
Where:

is the momentum of the electron
is the mass of the electron
From (1) we can find
:
(2)
(3)
Now, in order to find the wavelength of the electron
with this given kinetic energy (hence momentum), we will use the De Broglie wavelength equation:
(4)
Where:
is the Planck constant
So, we will use the value of
found in (3) for equation (4):
(5)
We are told the wavelength of the photon
is the same as the wavelength of the electron:
(6)
Therefore we will use this wavelength to find the energy of the photon
using the following equation:
(7)
Where
is the spped of light in vacuum
Finally:
Answer:
B) Friction
Explanation:
Friction is a force that acts when an object is sliding along a surface. Microscopically, this force is due to the fact that the two surfaces are not perfectly smooth, but they have "imperfections" that cause a force that opposes the motion of the object.
For an object sliding on a flat surface, the force of friction has magnitude:

where
is the coefficient of kinetic friction
m is the mass of the object
g is the acceleration of gravity
The direction of the force of friction is always opposite to the direction of motion of the object.
In reality, friction also acts if the object is at rest and it is pushed by a force; in this case, we talk about static friction, and its magnitude is

where
is called coefficient of static friction, and it is generally larger than the coefficient of kinetic friction.
Answer:
1/4 times your earth's weight
Explanation:
assuming the Mass of earth = M
Radius of earth = R
∴ the mass of the planet= 4M
the radius of the planet = 4R
gravitational force of earth is given as = 
where G is the gravitational constant
Gravitational force of the planet = 
=
=
recall, gravitational force of earth is given as = 
∴Gravitational force of planet = 1/4 times the gravitational force of the earth
you would weigh 1/4 times your earth's weight