Answer:
230kg would be the best answer
Explanation:
From Carnot's theorem, for any engine working between these two temperatures:
efficiency <= (1-tc/th) * 100
Given: tc = 300k (from question assuming it is not 5300 as it seems)
For a, th = 900k, efficiency = (1-300/900) = 70%
For b, th = 500k, efficiency = (1-300/500) = 40%
For c, th = 375k, efficiency = (1-300/375) = 20%
Hence in case of a and b, efficiency claimed is lesser than efficiency calculated, which is valid case and in case of c, however efficiency claimed is greater which is invalid.
Givens
=====
Ti = 92.8 oC = 92.8 + 273 = 365.8
T2 = 0.4 oC = 0.4 + 273 = 273.4
Vi = 1.54 mL
Vf = ?????
Formula
======
Vi/Ti = Vf / Tf
1.54 / 365.8 = Vf / 273.4
Calculations
=========
1.54 * 273.4 / 355.8 = Vf
vf = 1.15 mL
Comment
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if your teacher is concerned about sig digs, the answer is 1 mL. I'm not sure how to show that it is 1 sig dig. You can ask about this.
Answer:
0.83x10^-9 T
Direction is towards +z axis.
Explanation:
E = cB
E = magnitude of electrical 0.25 Em
c = speed of light in a vacuum 3x10^8 m/s
Therefore,
B = E/c = 0.25 ÷ 3x10^8
B = 0.83x10^-9 T
Magnetic fueld of a EM wave acts perpendicularly to its electric field, therefore it's direction is towards the +Z axis
