2.3 Transfer of thermal energy

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

Question 22

A student investigates the rate of cooling of water using two different containers: Beaker A (made of glass, unpainted) and Can B (made of metal, painted matt black). Both containers have the same volume of hot water ( $cm3200\text{ cm}^3$ ) and are closed with identical lids.

The student obtains the following temperature readings over a period of $s150\text{ s}$ at a constant room temperature of $22.0∘C22.0^\circ\text{C}$ :

Table 1: Beaker A (glass, unpainted)

$\text{s}$	$θ/∘C\theta / ^\circ\text{C}$
0	85.0
30	82.5
60	80.5
90	78.5
120	77.0
150	75.5

Table 2: Can B (metal, matt black)

$\text{s}$	$θ/∘C\theta / ^\circ\text{C}$
0	85.0
30	81.0
60	77.5
90	74.5
120	72.0
150	69.5

Calculate the total temperature drop $ΔθA\Delta\theta_{\text{A}}$ for Beaker A and $ΔθB\Delta\theta_{\text{B}}$ for Can B over the $s150\text{ s}$ interval.

[2]

State which container has the greater rate of cooling and justify your conclusion with reference to the temperature readings.

[2]

The student wants to find out if the difference in cooling rates is due to:

Factor 1: the matt black surface of the can being a better radiator of thermal energy than the unpainted glass,
Factor 2: the metal of the can being a better thermal conductor than the glass of the beaker.

Suggest two suitable changes that the student could make to the apparatus to investigate these factors separately.

[2]

2.3 Transfer of thermal energy

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

Question 22

The student obtains the following temperature readings over a period of $s150\text{ s}$ at a constant room temperature of $22.0∘C22.0^\circ\text{C}$ :

Table 1: Beaker A (glass, unpainted)

$\text{s}$	$θ/∘C\theta / ^\circ\text{C}$
0	85.0
30	82.5
60	80.5
90	78.5
120	77.0
150	75.5

Table 2: Can B (metal, matt black)

$\text{s}$	$θ/∘C\theta / ^\circ\text{C}$
0	85.0
30	81.0
60	77.5
90	74.5
120	72.0
150	69.5

Calculate the total temperature drop $ΔθA\Delta\theta_{\text{A}}$ for Beaker A and $ΔθB\Delta\theta_{\text{B}}$ for Can B over the $s150\text{ s}$ interval.

[2]

State which container has the greater rate of cooling and justify your conclusion with reference to the temperature readings.

[2]

The student wants to find out if the difference in cooling rates is due to:

Factor 1: the matt black surface of the can being a better radiator of thermal energy than the unpainted glass,
Factor 2: the metal of the can being a better thermal conductor than the glass of the beaker.

Suggest two suitable changes that the student could make to the apparatus to investigate these factors separately.

[2]

2.3 Transfer of thermal energy

Question 22

Markscheme

2.3 Transfer of thermal energy

Question 22

Markscheme

2.3 Transfer of thermal energy

Question 22

2.3 Transfer of thermal energy Questions

2.3 Transfer of thermal energy

Question 22

2.3 Transfer of thermal energy Questions