Answer:
According,to the law of conservation of energy,the amount of energy in a closed system always stay constant. ... So,the amount of work output and other transformed energy is equal to the amount of energy inputs. • In this way,the conservation of energy is fulfilled by the machines.
Answer:
10.52 m
Explanation:
The power radiated by a body is given by
P = σεAT⁴ where ε = emissivity = 0.97, T = temperature = 30 C + 273 = 303 K, A = surface area of human body = 1.8 m², σ = 5.67 × 10⁻⁴ W/m²K⁴
P = σεAT⁴ = 5.67 × 10⁻⁸ W/m²K⁴ × 0.97 × 1.8 m² × (303)⁴ = 834.45 W
This is the power radiated by the human body.
The intensity I = P/A where A = 4πr² where r = distance from human body.
I = P/4πr²
r = (√P/πI)/2
If the python is able to detect an intensity of 0.60 W/m², with a power of 834.45 W emitted by the human body, the maximum distance r, is thus
r = (√P/πI)/2 = (√834.45/0.60π)/2 = 21.04/2 = 10.52 m
So, the maximum distance at which a python could detect your presence is 10.52 m.
Construct a vector diagram. It will be a right-angled triangle. One vector (the hypotenuse) represents the heading of the boat, one represents the current and one represents the resultant speed of the boat, which I'll call x. Their magnitudes are 20, 3 and x. Let the required angle = theta. We have:
<span>theta = arcsin(3/20) = approx. 8.63° </span>
<span>The boat should head against the current in a direction approx. 8.63° to the line connecting the dock with the point opposite, or approx. 81.37° to the shore line. </span>
<span>x = sqrt(20^2 - 3^2) </span>
<span>= sqrt(400 - 9) </span>
<span>= sqrt 391 </span>
<span>The boat's crossing time = </span>
<span>0.5 km/(sqrt 391 km/hr) </span>
<span>= (0.5/sqrt 391) hr </span>
<span>= approx. 0.025 hr </span>
<span>= approx. 91 seconds</span>
The control setup in this experiment would be one tank that does not contain any of the additives. Since the tanks with the gasoline additives would need to be compared with a tank that is not affected by the results of these additives.
Answer:
Explanation:
Round to three significant digits
