Answer:
The distance from the pivot point that the small child will sit in order to maintain the balance is 1.8 m
Explanation:
Given;
mass of the bigger child, M = 30 kg
mass of the smaller child, m = 20 kg
distance between the two children, d = 3 m
This information can be represented diagrammatically;
3m
|<------------------------------------------------>|
----------------------------------------------------------------------------
↓ x Δ 3-x ↓
20kg 30kg
x is the distance from the pivot point that the small child will sit in order to maintain the balance
Take moment about the pivot;
Clockwise moment = anticlockwise moment
30(3-x) = 20x
90 -30x = 20x
90 = 20x + 30x
90 = 50x
x = 90 / 50
x = 1.8 m
Therefore, the distance from the pivot point that the small child will sit in order to maintain the balance is 1.8 m
Answer:
a) 3.242
b) 1291.178 KJ
c) 3.59 cents
Explanation:
a) First all the temperature units should be in Kelvin. -30°C + 273.15 = 243.15K and 45°C + 273.15 = 318.15K. Coefficient of performance for refrigerator is COP = TL/(TH-TL) where TL is Lower Temperature and TH is the Higher Temperature. COP = 243.15/(318.15-243.15) = 3.242
b) COP = Cooling Effect/Work Input. Cooling Effect (or Desired Output) is 4186 kJ.
So Work Input = Cooling Effect/COP = 4186KJ/3.242= 1291.178 KJ
c) 3.6 MJ (3600kJ) is for 10 cents, using ratio for cost: energy used
3.59 cents
<u>The color of an object is related to the wavelengths of light that are reflected and the wavelengths that are absorbed because:</u>
Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. The light with the longest wavelength is red, and light with the shortest wavelength is violet.
An opaque object doesn’t allow light to pass through it. But, it reflects or absorbs the light that strike it. Some objects like the leaves reflect one or a few wavelengths of visible light and absorb the others. The reflected wavelengths are used to find the color of an object as it is seen by the human eye. Example: The leaves are in green as they reflect green light and absorb the other wavelengths light. A transparent or translucent material, such as window glass, transmits some or all of the light that strikes it. This means that the light passes through the material rather than being reflected by it. Hence, we see the material because of the transmitted light. So the wavelength of the transmitted light is used to find the color that the object appears.
That would be a decomposer
Hope this helps!
