Answer:
-30° C
Explanation:
Data provided in the problem:
The formula for conversion as:
F = (9/5)C + 32
Now,
for the values of F = -22 , C = ?
Substituting the value of F in the above formula, we get
-22 = (9/5)C + 32
or
-22 - 32 = (9/5)C
or
(9/5)C = - 54
or
C = - 54 × (5/9)
or
C = - 30 °
Hence, -22 Fahrenheit equals to -30°C
Answer:
(d) A strong electron-phonon interaction
Explanation:
Superconductivity -
The phenomenon of superconductivity is due to the attractive force between electrons from the exchange of the phonons that cause the bound pair of electrons known as cooper pairs .
A strong electron -phonon intercation is suitable condition for superconductivity and high resistance .
If no frictional work is considered, then the energy of the system (the driver at all positions is conserved.
Let
position 1 = initial height of the diver (h₁), together with the initial velocity (v₁).
position 2 = final height of the diver (h₂) and the final velocity (v₂).
The initial PE = mgh₁ and the initial KE = (1/2)mv₁²
where g = acceleration due to gravity,
m = mass of the diver.
Similarly, the final PE and KE are respectively mgh₂ and (1/2)mv₂².
PE in position 1 is converted into KE due to the loss in height from position 1 to position 2.
Therefore
(KE + PE) ₁ = (KE + PE)₂
Evaluate the given answers.
A) The total mechanical energy of the system increases.
FALSE
B) Potential energy can be converted into kinetic energy but not vice versa.
TRUE
C) (KE + PE)beginning = (KE + PE) end.
TRUE
D) All of the above.
FALSE
Answer: D
Explanation: Resistance of current in a wire is directly proportional to the length of the wire and inversely proportional to the cross - sectional area of the wire. That is,
R = (rho × L)/A
Where
L = length of the wire
A = cross sectional Area of the wire
rho = resistivity = proportionality constant which depends on the quality of the wire.
Therefore, Resistance and resistivity are related by a:
proportionality constant dependent on the identity of the material.
(C) 200 N
Explanation:
The acceleration due to gravity on earth
is given by

where
= universal gravitational constant
= mass of the earth
= radius of the earth
Planet Krypton has twice the mass of earth and 3 times the radius so its acceleration due to gravity
is



or

If we multiply both sides by Superman's mass, we get his weights on both planets:

