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ANEK [815]
3 years ago
14

Problem 3.

Physics
1 answer:
Korolek [52]3 years ago
8 0

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.

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For an object like a planet, with a typical temperature of a few hundred kelvin, what kind of blackbody radiation would it princ
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Answer:

Low-temperature blackbody

Explanation:

There are 3 types of blackbody temperatures.

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A Low-temperature blackbody is a type of black body radiation that has the range of -40° C to 175° C, typically between 233 K and 448 K. A perfect fit for the temperature range mentioned in the question, "a few hundred Kelvin". Therefore, it's the kind of blackbody temperature that the object would emit.

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What causes a hypothesis to be rejected?
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If the statistical analysis shows that the significance level is below the cut off value they have set (either 0.05 or 0.01) they reject the null hypothesis and accept the alternative hypothesis
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A war wolf is a device used during the middle ages to assault fortifications with large rocks. A simple trebuchet is constructed
Katarina [22]

Answer:v=41.23 m/s

Explanation:

Given

mass of heavy object m_1=52 kg

distance of m_1 from the axle r_1=14 cm

mass of rock m_2=123 gm

Length of rod =4.1 m

distance of m_2 from axle r_2=4.1-0.14=3.96 m

Net torque acting is

T_{net}=m_1gr_1-m_2gr_2

T_{net}=52\times 0.14\times g-0.123\times 3.96\times g

T_{net}=6.793\times 9.8

T_{net}=66.57 N-m

Work done by T_{net} is converted to rock kinetic Energy

thus

T_{net}\times \theta =\frac{mv^2}{2}

Where \theta =angle\ turned =\frac{\pi }{2}

v= velocity\ at\ launch

66.57\times \frac{\pi }{2}=\frac{0.123\times v^2}{2}

v^2=66.57\times \pi

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3 0
3 years ago
Electrical wire with a diameter of .5 cm is wound on a spool with a radius of 30 cm and a height of 24 cm.
kow [346]

Answer:

a)   # lap = 301.59 rad , b)   L = 90.48 m

Explanation:

a) Let's use a direct proportions rule (rule of three). If one turn of the wire covers 0.05 cm, how many turns do you need to cover 24 cm

          # turns = 1 turn (24 cm / 0.5 cm)

         # laps = 48 laps

Let's reduce to radians

        # laps = 48 laps (2 round / 1 round)

       # lap = 301.59 rad

b) Each lap gives a length equal to the length of the circle

          L₀ = 2π R

          L = # turns L₀

          L = # turns 2π R

          L = 48 2π 30

          L = 9047.79 cm

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