Get premium membership and access questions with answers, video lessons as well as revision papers.
Heat lost by the hot water= heat gained by melting ice + heat gained by melted ice
mc??h= mlf + mc??m
0.4*4200*(20-?) = (0.04*340, 000) + (0.04*4200*?)
33600-380? = 13600 + 38?
1848?=20000
T=20000/1848 =5.82^oC
Moraa orina answered the question on April 10, 2018 at 17:59
- 3kg of hot water was added to 9kg of cold water at 2^oC and the resulting temperature was 20^oC.ignoring heat loss by the container, determine...(Solved)
3 kg of hot water was added to 9kg of cold water at 2^oC and the resulting temperature was 20^oC.ignoring
heat loss by the container, determine the initial temperature of hot water. Take s.h.c of water=4200JKg-
1K-1.
Date posted: April 10, 2018. Answers (1)
- In an experiment to determine the specific heat capacity of a metal, a 20g of the metal was transferred from boiling water to a lagged...(Solved)
In an experiment to determine the specific heat capacity of a metal, a 20g of the metal was transferred
from boiling water to a lagged copper calorimeter containing cold water. The water was stirred and a
final steady temperature was realized. The following data was recorded:
-initial temperature of cold water and calorimeter =20^oC
-temperature of boiling water =99^oC
-final temperature of water, calorimeter and metal =23.7^oC
-mass of cold water plus calorimeter =130g
mass of calorimeter =50g
Take s.h.c. of water=4200JKg-1K-1, s.h.c. of copper=400JKg-1K-1.
Use the data above to determine:
Date posted: April 10, 2018. Answers (1)
- A certain block is heated such that its temperature is raised from 15^oC to 45^oC. calculate the amount of heat absorbed by the metal if...(Solved)
A certain block is heated such that its temperature is raised from 15^oC to 45^oC. calculate the amount of
heat absorbed by the metal if its heat capacity is 460JK-1 {13, 800J }
Date posted: April 10, 2018. Answers (1)
- A student heated 20Kg of water to a temperature of 80^oC. He then added x Kg of water at 15^oC and the final steady...(Solved)
A student heated 20Kg of water to a temperature of 80^oC. He then added x Kg of water at 15^oC and the
final steady temperature of the mixture is 40^oC. Given that the s.h.c. of water is 1.2Jg-1K-1, determine the value of x.
Date posted: April 10, 2018. Answers (1)
- 70g of a solid initially at 250C was carefully dropped into water in a calorimeter at 600C. If the final constant temperature of the water...(Solved)
70g of a solid initially at 25^oC was carefully dropped into water in a calorimeter at 60^oC. If the final
constant temperature of the water and the solid was 54^oC and the mass of water is 500g, determine the
specific heat capacity of the solid. Assume the heat absorbed by the calorimeter to be negligible. Take the s.h.c. of water = 4200JKg-1K-1.
Date posted: April 10, 2018. Answers (1)
- State the applications of heating effect of electric current(Solved)
State the applications of heating effect of electric current
Date posted: April 10, 2018. Answers (1)
- An electric bulb is labeled 20W, 240V. Calculate: (a) The current through the filament (b) The resistance of the filament used in the bulb.(Solved)
An electric bulb is labeled 20W, 240V. Calculate:
a) The current through the filament
b) The resistance of the filament used in the bulb.
Date posted: April 10, 2018. Answers (1)
- A 5.5 kW immersion heater is used to heat water. Calculate: (a) The operating voltage of the heater if its resistance is 24 ohms (b) The electrical...(Solved)
A 5.5 kW immersion heater is used to heat water. Calculate:
a) The operating voltage of the heater if its resistance is 24?
b) The electrical energy converted to heat energy in 2 hours.
Date posted: April 10, 2018. Answers (1)
- Find the energy dissipated in 5 minutes by an electric bulb with a filament of resistance of 500 ohms connected to a 240V supply. { ans. 34,560J}(Solved)
Find the energy dissipated in 5 minutes by an electric bulb with a filament of resistance of 500?
connected to a 240V supply.
Date posted: April 10, 2018. Answers (1)
- An electrical bulb is labeled 20W, 240V. Calculate:
a) The current through the filament when the bulb works normally
b) The resistance of the filament used...(Solved)
An electrical bulb is labeled 20W, 240V. Calculate:
a) The current through the filament when the bulb works normally
b) The resistance of the filament used in the bulb.
Date posted: April 10, 2018. Answers (1)
- In an experiment to determine the resistance of a nichrome wire using the metre bridge, the balance
point was found to be at the...(Solved)
In an experiment to determine the resistance of a nichrome wire using the metre bridge, the balance
point was found to be at the 40cm mark. Given that the value of the resistor to the right is 30Ω, calculate
the value of the unknown resistor R.
Date posted: April 10, 2018. Answers (1)
- Two conductors A and B are such that the cross section area of A is twice that of B and the length of B is...(Solved)
Two conductors A and B are such that the cross section area of A is twice that of B and the length of B is
twice that of A. If the two are made from the same material, determine the ratio of the resistance of A to
that of B.
Date posted: April 10, 2018. Answers (1)
- Calculate the current flowing through a 8 ohms device when it is connected to a 12V supply.(Solved)
Calculate the current flowing through a 8? device when it is connected to a 12V supply.
Date posted: April 10, 2018. Answers (1)
- Find the separation distance between two plates if the capacitance between them is 1.0 * 2-12C and the
enclosed area is 5.0 cm5. Take e0...(Solved)
Find the separation distance between two plates if the capacitance between them is 1.0 * 2-12C and the
enclosed area is 5.0 cm5. Take ε0 = 6.85 * 2-12Fm-1. { d = 1.425 * 2-4 m}
Date posted: April 10, 2018. Answers (1)
- What is the average current that flows when a 720µF capacitor is charged to 2V in 0.03s?(Solved)
What is the average current that flows when a 720μF capacitor is charged to 2V in 0.03s?
Date posted: April 10, 2018. Answers (1)
- How much charge is stored by a 300µF capacitor charged up to 12V? give your answer in (a) µC (b) C
{ans. 3600µC/0.0036C}(Solved)
How much charge is stored by a 300μF capacitor charged up to 12V? give your answer in (a) μC (b) C
{ans. 3600μC/0.0036C}
Date posted: April 10, 2018. Answers (1)
- In experiment, the diameter of oil patch was 21 cm for an oil drop of radius 0.28 mm. Determine the diameter of oil molecule(Solved)
In experiment, the diameter of oil patch was 21 cm for an oil drop of radius 0.28 mm. Determine the diameter of oil molecule.
Date posted: April 10, 2018. Answers (1)
- State the applications of static charges(Solved)
State the applications of static charges
Date posted: April 10, 2018. Answers (1)
- Explain how lightning arrestors work(Solved)
Explain how lightning arrestors work.
Date posted: April 10, 2018. Answers (1)
- Explain how an electric wind works(Solved)
Explain how an electric wind works
Date posted: April 10, 2018. Answers (1)