Answer:
143.352 watt.
Explanation:
So, in the question above we are given the following parameters or data or information that is going to assist us in answering the question above efficiently. The parameters are:
"A 1.8 m wide by 1.0 m tall by 0.65m deep home freezer is insulated with 5.0cm thick Styrofoam insulation"
The inside temperature of the freezer = -20°C.
Thickness = 5.0cm = 5.0 × 10^-2 m.
Step one: Calculate the surface area of the freezer. That can be done by using the formula below:
Area = 2[ ( Length × breadth) + (breadth × height) + (length × height) ].
Area = 2[ (1.8 × 0.65) + (0.65 × 1.0) + (1.8 × 1.0)].
Area = 7.24 m^2.
Step two: Calculate the rate of heat transfer by using the formula below;
Rate of heat transfer =[ thermal conductivity × Area (T1 - T2) ]/ thickness.
Rate of heat transfer = 0.022 × 7.24(25+20)/5.0 × 10^-2 = 143.352 watt.
Answer:
a) 3.37 x 
b) 6.42kg/
Explanation:
a) Firstly we would calculate the volume of the metal using it`s weight in air and water , after finding the weight we would find the density .
Weight of metal in air = 50N = mg implies the mass of metal is 5kg.
Now the difference of weight of the metal in air and water = upthrust acting on it = volume (metal) p (liquid) g = V (1000)(10) = 14N. So volume of metal piece = 14 x 
. So density of metal = mass of metal / volume of metal = 5 / 14 x = 3.37 x
b) Water exerts a buoyant force to the metal which is 50−36 = 14N, which equals the weight of water displaced. The mass of water displaced is 14/10 = 1.4kg Since the density of water is 1kg/L, the volume displaced is 1.4L. Hence, we end up with 3.57kg/l. Moreover, the unknown liquid exerts a buoyant force of 9N. So the density of this liquid is 6.42kg/
Wavelength = (speed) / (frequency)
Wavelength = (300 thousand km per second) / (10.5 billion per second)
Wavelength = (300 / 10.5) (thousand km per second) / (billion per second)
Wavelength = (28.57) (million meters / second) / (thousand million / second)
Wavelength = (28.57) (meters / second) / (thousand / second)
Wavelength = (28.57) (meters / thousand)
<em>Wavelength = (28.57) (millimeters) </em>
Given :
An object 50 cm high is placed 1 m in front of a converging lens whose focal length is 1.5 m.
To Find :
the image height (in cm).
Solution :
By lens formula :
Here, u = - 100 cm
f = 150 cm
Now, magnification is given by :
Therefore, the image height is 3 m or 300 cm.
Answer:
Explanation:
Theoretical efficiency = T₁ - T₂ / T₁ where T₁ and T₂ is absolute temperature of hot and cold end of the heat engine.
= 600 / (273 + 700 )
= 600 / 973
= .6166
operating efficiency = 40% of .6166
= .4 x .6166
= .2466 = 24.66 %
efficiency = work output / heat input
= 5000 / heat input = .2466
heat input = 5000 / .2466
= 20275.75 J .
HEAT EXTRACED = 20275.75 J.
