Calculate the temperature rise of a mass due to energy transfer over time.

Specific question: The hot tub system has a volume of 4.5 m3 and is filled with water at a temperature of 28 °C. The heater transfers thermal energy to the water at a rate of 2.7 kW while a pump circulates the water. Assume that no heat is transferred to the surroundings. Calculate the rise in water temperature that the heater could produce in 1.0 hour. Density of water = 1000 kg m^-3 . Specific heat capacity of water = 4200 J kg–1 K–1We begin with the specific heat capacity equation: Energy = Mass x Specific heat capacity(S.H.C) x Tempchange. Rearranging for Temperature change we get: TempChange = Energy/ (Mass x S.H.C). We are given the S.H.C and so only need to obtain the mass and the energy.We can observe that the volume and density is given and using the equation Mass = Volume x Density , we can calculate the mass by doing 4.5 x 1000 = 4500Kg. Now we need energy. To do this we are given the power and time. Relating them by using Power = Energy/Time and hence Energy = Power x Time we can input the given values to arrive at 2.7 x 1000 x 3600 = 9720000J. Now we just input the values we have found into the equation for temperature change giving us:Temperature Change = 9720000 / ( 4500 x 4200) = 0.51 K. Throughout, make sure to check the units of the values used!Eg , Energy is in Joules. So Power must me in Joules per Second (Watts) and Time must therefore be in Seconds.This is why the power is multiplied by 1000 for example as kW is the unit for 1000 Watts and the Time is converted from 1 hour to 60 x 60 seconds = 3600 seconds.

DS
Answered by Denis S. Physics tutor

15815 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

A ball is rolled, travelling 10 m north in 5s, then 10 m east in 10s. What is the total distance and average speed of the ball? What is the total displacement and average velocity of the ball?


Explain the findings from Rutherford's alpha particle scattering experiment.


A wire has length l, cross-sectional area a, resistivity p and resistance R. It is compressed to a third of its original length but its volume and resistivity are constant. Show its new resistance is R/9.


A boy (25kg) and a girl (20kg) are playing on a see-saw which is 4m long. If the boy sits 1m from the centre on the left side and the girl 2m from the centre on the other, which direction will the see-saw will rotate around its centre?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences