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:
a) 24.4 Ω
b) 4.92 A
c) 495.9 W
d)
c. It will be larger. The resistance will be smaller so the current drawn will increase, increasing the power.
Explanation:
b)
The formula for power is:
P = IV
where,
P = Power of heater = 590 W
V = Voltage it takes = 120 V
I = Current Drawn = ?
Therefore,
590 W = (I)(120 V)
I = 590 W/120 V
<u>I = 4.92 A</u>
<u></u>
a)
From Ohm's Law:
V = IR
R = V/I
Therefore,
R = 120 V/4.92 A
<u>R = 24.4 Ω</u>
<u></u>
c)
For constant resistance and 110 V the power becomes:
P = V²/R
Therefore,
P = (110 V)²/24.4 Ω
<u>P = 495.9 W</u>
<u></u>
d)
If the resistance decreases, it will increase the current according to Ohm's Law. As a result of increase in current the power shall increase according to formula (P = VI). Therefore, correct option is:
<u>c. It will be larger. The resistance will be smaller so the current drawn will increase, increasing the power.</u>
The speed of an object in a set direction is its velocity.
Expression to calculate energy from voltage: E= V*Q where E= energy, V= voltage, and Q= charge
Additional help:
-To find the Voltage ( V )
[ V = I x R ] V (volts) = I (amps) x R (Ω)
-To find the Current ( I )
[ I = V ÷ R ] I (amps) = V (volts) ÷ R (Ω)
-To find the Resistance ( R )
[ R = V ÷ I ] R (Ω) = V (volts) ÷ I (amps)
I hope that helps to some extent-