Explanation:
It is given that,
Mass of an electron, 
Initial speed of the electron, 
Final speed of the electron, 
Distance, d = 5 cm = 0.05 m
(a) The acceleration of the electron is calculated using the third equation of motion as :
Force exerted on the electron is given by :
(b) Let W is the weight of the electron. It can be calculated as :
Comparison,
Hence, this is the required solution.
Answer:
B.The force of friction between the block and surface will decrease.
Explanation:
The force of friction is given by
where 
is the coefficient of friction and 
is the normal force.
When the student pulls on the block with force 
at an angle 
, the normal force on the block becomes
and hence the frictional force becomes
.
Now, as we increase , 
increases which as a result decreases the normal force 
, which also means the frictional force decreases; Hence choice B stands true.
<em>P.S: Choice D is tempting but incorrect since the weight </em><em> is independent of the external forces on the block. </em>
The energy of a photon is given by:
where h is the Planck constant and f is the photon frequency.
We know the energy of the photon,
, so we can rearrange the equation to calculate the frequency of the photon:
And now we can use the following relationship between frequency f, wavelength
and speed of light c to find the wavelength of the photon:
Answer:
bend toward the normal line
Explanation:
When light passes from a less dense to a more dense substance, (for example passing from air into water), the light is refracted (or bent) towards the normal. In your question the light is moving from rarer to denser medium
