Answer:
a) 1450watts
b) 564watts
c) 1.11
Explanation:
Power consumed = IV
I is the current rating
V is the operating voltage
If a blow-dryer and a vacuum cleaner each operate with a voltage of 120 V and the current rating of the blow-dryer is 12 A, while that of the vacuum cleaner is 4.7 A then their individual power rating is calculated thus;
a) For blow-dryer
Operating voltage = 120V
Its current rating = 12A
Power consumed = IV
= 120×12
= 1440watts
b) For vacuum cleaner:
Operating voltage is the same as that of blow dryer = 120V
Its current rating = 4.7A
Power consumed = IV
= 120×4.7
= 564watts
c) Energy used = Power consumed × time taken
Energy used = Power × time
Energy used by blow dryer = 1440×20×60
= 1,728,000Joules
Energy used up by vacuum cleaner = 564×46×60
= 564×2760
= 1,556,640Joules
Ratio of the energy used by the blow-dryer in 20 minutes to the energy used by the vacuum cleaner in 46 minutes will be 1,728,000/1,556,640 = 1.11
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<span><span>The
best and most correct answer among the choices provided by the question is </span>B.-2.71 V.</span>
Mg2+(aq) + 2e- -> Mg(s) E=-2.37 V
Cu2+(aq) + 2e- -> Cu(s) E =+ 0.34 V
Since Cu is acting as the anode, the equation needs to be
reversed.
Cu(s) -> Cu2+(aq) + 2e- E =- 0.34 V
Ecell= -2.37 V+ (- 0.34 V) = -2.71 V
<span><span>
</span><span>Hope my answer would be a great help for you. </span> </span>
<span> </span>
Answer:
93312000 Joules
Explanation:
Energy can be explained as the capacity for doing work. And can be expressed as
E= pt....................eqn(1)
Where
E= Energy in Joules
P= power in Watt= 2.00W
t= time in seconds
Time= 18 months, which can be converted to "seconds" as;
18 months = [ 18 monthsx 30 days x 24 hours x 60 min x 60 sec] = 46656000
Then
time= 46656000 seconds
Power=2 watt
If we substitute into equation (1) we have
Energy = 2 watt × 46656000 seconds
Energy= 93312000 Joules
Answer:
100nm-280nm
Explanation:
Ultraviolet rays (UV) are part of the electromagnetic spectrum. It goes from 10nm to 400nm wavelengths, they are shorter than visible light, thus it's impossible to see by a human eye, and larger than X-rays (used in many medical applications and harmful when long-exposed).
According to its wavelengths, UV can be divided in different types:
UVA: long wave UV (315nm-400nm)
UVB: medium-wave UV (280nm-315nm)
UVC: short wave UV (100nm-280nm)
Therefore, UVC comprises wavelengths between 10nm and 280nm.
The work-energy principle states that the work done by all the non-conservative forces acting on an object (or system of objects) causes a change in the total mechanical energy of the object or system.
What is the work-energy principle?
The work-energy principle states that the total work done on a system is equal to the change in kinetic energy of the system. It is given as:
W.D = ΔK.E
= K.E₁ - K.E₂
where K.E₁ is the initial kinetic energy of the system
K.E₂ is the final kinetic energy of the system
What is meant by non-conservative forces?
Non-conservative forces as the name suggests are not conserved i.e. these forces cause a loss of mechanical energy from the system. A prime example of non-conservative forces is friction.
The total mechanical energy of the system is the sum of the potential energy and kinetic energy that the system contains. This energy is conserved and follows the work-energy theorem.
Learn more about work and energy here:
<u>brainly.com/question/17290830</u>
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