Answer:
Explanation:
Astronauts face a wide range of dangers when maneuvering in space. Collecting rock samples requires breaking apart rocks on the moon's surface, which requires tools. These tools are sometimes small hammers or other times special drills. All of this process means moving and using force to break these rocks apart and every single movement can cause a mistake which can lead to a piece of the suit ripping or a failure in the machinery. Since there is no oxygen on the moon the tiniest failure in the suit can lead to the death of the astronaut. Therefore, having backup safety precautions, and quick repair scenarios is a must when collecting rock samples on the moon.
The correct option is B.
As we are told in the question, the cabbage and broccoli grow best in clay soil. From the options we are given, it can be seen that it is only option B that has the highest amount of clay soil. The soil that will be used should be one that has the highest content of clay.
Answer: Option (A) is the correct answer.
Explanation:
Convection is a process in which heat transfers from a hotter substance to a colder substance.
As a result, the substance which is less dense will rise and the more denser substance will sink due to the influence of gravity.
Thus, we can conclude that in the given situation substance X will rise due to convection.
0.0179 ohms for copper.
0.0184 ohms for annealed copper
Ď = R (A/l) where
Ď = electrical resistivity
R = electrical resistance of a uniform specimen
A = cross sectional area
l = length
Solve for R by multiplying both sides by l/A
R = Ď(l/A)
The cross section of the wire is pi * 1^2 mm = 3.14159 square mm = 3.14159e-6 square meters.
The length is 3 meters. So l/A = 3/3.14159e-6 = 9.5493e5
Ď for copper is 1.68e-8 so 1.68e-8 * 9.5493e5 = 1.60e-2 ohms at 20 C
But copper has a temperature coefficient (α) of 0.00386 per degree C.
So the resistance value needs to be adjusted based upon how far from 20 C the temperature is.
50 - 20 = 30 C
So 0.00386 * 30 = 0.1158 meaning that the actual resistance at 50 C will be 11.58% higher.
So 1.1158 * 0.016 = 0.0179 ohms.
If you're using annealed copper, the values for Ď and the temperature coefficient change.
Ď = 1.72e-8
α = 0.00393
Doing the math, you get
1.72e-8 * 9.5493e5 * (1 + 30 * 0.00393) = 0.0184 ohms
