Answer:
T0=390 degF
Explanation:
The thermometer reading 70◦Fis placed in an oven preheated to a constant temperature. Through the glass window in the oven door, an observer records that the thermometer reads 110◦F after 12 minutes and 145◦F after 1 minute. How hot is the oven? Newton’s law of cooling yields the following differential equationdTdt=k(T−T0), whereT0 is the ambient temperature.
If T is temperature, then by Newton’s law
dTdt=-k(T−T0)
Where
T0− is temperature of oven
∫
ln(T-T0), from 110 to 70=-kt, from 1/2 to 0
ln(110-T0)-ln(70-T0)=-k(1/2-0)
integrating the LHS of the equation from 110 to 145F
∫∫∫
ln(145-T0)-ln(110-T0)=-k(1-1/2)
2ln145-T0/(110-T0)=-k
k=-2lnT0-145/(T0-110).......................2
couplijng equatiuon 2 with 1
(T0-110)^2=(T0-70)(T0-145)
T0^2-220T0+12100=T0^2-215T0+10150
5T0=1950
T0=390 degF
Answer:
3349J/kgC
Explanation:
Questions like these are properly handled having this fact in mind;
Quantity of heat = mcΔ∅
m = mass of subatance
c = specific heat capacity
Δ∅ = change in temperature
m₁c₁(∅₂-∅₁) = m₂c₂(∅₁-∅₃)
m₁ = mass of block = 500g = 0.5kg
c₁ = specific heat capacity of unknown substance
∅₂ = block initial temperature = 50oC
∅₁ = equilibrium temperature of block and water after mix= 25oC
m₂= mass of water = 2kg
c₂ = specific heat capacity of water = 4186J/kg C
∅₃ = intial temperature of water = 20oC
0.5c₁(50-25) = 2 x 4186(25-20)
And we can find c₁ which is the unknown specific heat capacity
c₁ = 
= 3348.8J/kg C≅ 3349J/kg C
Answer:
potential energy or stored energy
Explanation:
The first thing you should know to solve this problem is the conversion of pounds to kilograms:
1lb = 0.45 Kg
We can solve this problem by a simple rule of three
1lb ---> 0.45Kg
125lb ---> x
Clearing x we have:
x = ((125) / (1)) * (0.45) = 56.25 Kg.
Answer
her mass expressed in kilograms is 56.25 Kg.
Answer:
v = 10 m/s
Explanation:
Given that,
Distance covered by a sprinter, d = 100 m
Time taken by him to reach the finish line, t = 10 s
We need to find his average velocity. We know that velocity is equal to the distance covered divided by time taken. So,
v = d/t
Hence, his average velocity is 10 m/s.
