Answer:
Work done, W = 2675.4 J
Given:
mass, m = 70.0 kg
height, H = 3.90 m
Solution:
According to the question, as the person jumps the stairs up, there is an increase in the potential energy of the person which is provided by the work done in climbing the stairs and is given by:
Work done, W = mgH
where
g = acceleration due to gravity = ![9.8 m/s^{2}[tex][tex]W = 70.0\times 9.8\times 3.90 = 2675.4 J](https://tex.z-dn.net/?f=9.8%20m%2Fs%5E%7B2%7D%5Btex%5D%3C%2Fp%3E%3Cp%3E%5Btex%5DW%20%3D%2070.0%5Ctimes%209.8%5Ctimes%203.90%20%3D%202675.4%20J)
Answer:
Alloy, metallic substance composed of two or more elements, as either a compound or a solution. The components of alloys are ordinarily themselves metals, though carbon, a nonmetal, is an essential constituent of steel.
Explanation:
Alloys are usually produced by melting the mixture of ingredients. The value of alloys was discovered in very ancient times; brass (copper and zinc) and bronze (copper and tin) were especially important. Today, the most important are the alloy steels, broadly defined as steels containing significant amounts of elements other than iron and carbon. The principal alloying elements for steel are chromium, nickel, manganese, molybdenum, silicon, tungsten, vanadium, and boron have a wide range of special properties, such as hardness, toughness, corrosion resistance, magnetizability, and ductility. Nonferrous alloys, mainly copper–nickel, bronze, and aluminum alloys, are much used in coinage. The distinction between an alloying metal and an impurity is sometimes subtle; in aluminum, for example, silicon may be considered an impurity or a valuable component, depending on the application, because silicon adds strength though it reduces corrosion resistance.
What is the heat extracted from the cold reservoir for the refrigerator shown in(Figure 1) ? Assume that W1 = -123J and W2 = 88J .
<span>Qc= _________ </span>
<span>Part B
</span>
K=105J
Answer:

Explanation:
Let x be the distance to the shore
From trigonometry properties:
