Answer:
Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases.
Let's see sentence-by-sentence:
<span>- Objects within the focal length will create real images. --> false
In fact, objects within the focal length create virtual images, as it can be seen in the ray diagrams here:
https://upload.wikimedia.org/wikipedia/commons/4/47/Concavemirror_raydiagram_F.svg
- Concave mirrors converge distant parallel light rays on the focal point. --> TRUE: the parallel rays (with respect to the mirror's axis) are reflected back into the focal point of the mirror, as it can be seen also from the previous picture.
- Concave mirrors can only create real images. --> FALSE: as it can be seen from the first picture, when the object is between the focus and the mirror, its image is virtual.
Concave mirrors can create real and virtual images. --> TRUE: concave mirrors can create real and virtual images, depending on the position of the object.
- Objects far away from concave mirrors will appear enlarged. --> FALSE:
as it can be seen from the ray diagram, the size of the image is smaller than the size of the object. https://upload.wikimedia.org/wikipedia/commons/d/d2/Concavemirror_raydiagram_2F.svg
- Objects between the center of curvature and the focal point will create real images.--> TRUE: as it can be seen from the ray diagram (2F corresponds to the center of curvature), the image in this case is on the same side of the object, so it is real. </span>https://upload.wikimedia.org/wikipedia/commons/9/91/Concavemirror_raydiagram_2FE.svg
Heat and Temperature are physical properties of a body. While heat is a form of energy, temperature is a measure of how hot a body is. Temperature is directly proportional to the heat of the body, so when heat is introduced, the temperature of the body increases. Hope this helped!
The maximum allowable torque must correspond to the allowable shear stress for maximization. To solve this, we use the torsion formula:
Max. Allowable Shear Stress = Maximum Torque ÷ Cross-Sectional Area
8 x 10^6 Pa = Maximum Torque ÷ pi*(d/2)²
Maximum Torque = 8 x 10^6 Pa * pi*(0.06/2)² m²
Maximum Torque = 22,619.47 J or
Maximum Torque = 22.62 kJ
As for the second question, I have no reference figure so I am unable to answer it. I hope I was still able to help you, though.