19.
diagram: ice wrapped in wire gauze, not melted; water boiling at top, heat applied.
the diagram above illustrates the set-up for an experiment on heat conduction. the experiment demonstrates that
a. ice is a poor conductor of heat.
b. water is a poor conductor of heat.
c. water can boil at any temperature.
d. ice is denser than water.

20. the following concepts are methods of heat transfer except
a. conduction.
b. convention.
c. convection.
d. radiation.

21. a given mass of gas at a pressure of 400 pa has a temperature of 30 °c. if its volume remains constant, calculate the pressure at 40 °c.
a. 533.3 pa
b. 413.2 pa
c. 387.2 pa
d. 300.0 pa

22. a metal of mass 200 g is heated from 60 °c to 75 °c. calculate the quantity of heat supplied. specific heat capacity of the metal = 400 j kg⁻¹ k⁻¹
a. 1.08 × 10⁷ j
b. 1.20 × 10⁵ j
c. 1.08 × 10⁴ j
d. 1.20 × 10³ j

23. diagram: lever with 120n load 2m from fulcrum, effort 8m from fulcrum.
in the lever system illustrated above, the effort required to keep the bar in horizontal equilibrium is
a. 60 n.
b. 30 n.
c. 15 n.
d. 12 n.

24. which of the following devices applies pascal’s principle?
a. lift pump
b. force pump
c. hydraulic press
d. syringe

turn ov

Question

19.
diagram: ice wrapped in wire gauze, not melted; water boiling at top, heat applied.
the diagram above illustrates the set-up for an experiment on heat conduction. the experiment demonstrates that
a. ice is a poor conductor of heat.
b. water is a poor conductor of heat.
c. water can boil at any temperature.
d. ice is denser than water.

20. the following concepts are methods of heat transfer except
a. conduction.
b. convention.
c. convection.
d. radiation.

21. a given mass of gas at a pressure of 400 pa has a temperature of 30 °c. if its volume remains constant, calculate the pressure at 40 °c.
a. 533.3 pa
b. 413.2 pa
c. 387.2 pa
d. 300.0 pa

22. a metal of mass 200 g is heated from 60 °c to 75 °c. calculate the quantity of heat supplied. specific heat capacity of the metal = 400 j kg⁻¹ k⁻¹
a. 1.08 × 10⁷ j
b. 1.20 × 10⁵ j
c. 1.08 × 10⁴ j
d. 1.20 × 10³ j

23. diagram: lever with 120n load 2m from fulcrum, effort 8m from fulcrum.
in the lever system illustrated above, the effort required to keep the bar in horizontal equilibrium is
a. 60 n.
b. 30 n.
c. 15 n.
d. 12 n.

24. which of the following devices applies pascal’s principle?
a. lift pump
b. force pump
c. hydraulic press
d. syringe

turn ov

Accepted Answer

### Question 19
# Brief Explanations:
In the heat conduction experiment, ice wrapped in wire gauze doesn't melt while water at the top boils. This shows heat doesn't conduct well through ice, so ice is a poor conductor. Option B is wrong (water can conduct, and the experiment doesn't show that). Option C is wrong (water boils at 100°C at standard pressure). Option D is wrong (ice is less dense than water).
# Answer: A. ice is a poor conductor of heat

### Question 20
# Brief Explanations:
The three methods of heat transfer are conduction, convection, and radiation. "Convention" is a misspelling (should be convection, but the option has "convention" which is not a heat transfer method).
# Answer: B. convention

### Question 21
# Explanation:
## Step1: Recall Gay - Lussac's Law (constant volume, $ \frac{P_1}{T_1}=\frac{P_2}{T_2} $, $ T $ in Kelvin)
First, convert temperatures to Kelvin. $ T_1 = 30 + 273 = 303\space K $, $ T_2 = 40+ 273 = 313\space K $, $ P_1 = 400\space Pa $
## Step2: Solve for $ P_2 $
From $ \frac{P_1}{T_1}=\frac{P_2}{T_2} $, we get $ P_2=\frac{P_1T_2}{T_1} $
Substitute values: $ P_2=\frac{400\times313}{303}\approx\frac{125200}{303}\approx413.2\space Pa $
# Answer: B. 413.2 Pa

### Question 22
# Explanation:
## Step1: Recall heat formula $ Q = mc\Delta T $
Mass $ m = 200\space g=0.2\space kg $, specific heat $ c = 400\space J\space kg^{-1}\space K^{-1} $, $ \Delta T=75 - 60 = 15\space K $
## Step2: Calculate $ Q $
$ Q=0.2\times400\times15 = 0.2\times6000 = 1200\space J = 1.20\times 10^{3}\space J $ (Wait, there's a mistake. Wait, $ 0.2\times400\times15 = 1200 = 1.2\times 10^{3} $, but option B is $ 1.20\times 10^{3}\space J $, option C is $ 1.08\times 10^{4}\space J $. Wait, maybe I miscalculated. Wait, $ m = 200g = 0.2kg $, $ c = 400J/kgK $, $ \Delta T = 15K $. $ Q=mc\Delta T=0.2\times400\times15 = 1200J=1.2\times 10^{3}J $. But let's check again. Wait, maybe the specific heat is 400 J/kg°C (same as K). Wait, 200g is 0.2kg. 0.2*400*15 = 1200 J. So the answer is B? Wait, no, 1.20×10³ J is 1200 J. Wait, the options: A. 1.08×10⁷ J, B. 1.20×10³ J, C. 1.08×10⁴ J, D. 1.20×10⁷ J. So yes, B.
## Step1: Convert mass to kg: $ m = 200\space g=\frac{200}{1000}=0.2\space kg $
## Step2: Calculate temperature change: $ \Delta T=75 - 60 = 15\space ^\circ C=15\space K $
## Step3: Use $ Q = mc\Delta T $
$ Q = 0.2\space kg\times400\space J\space kg^{-1}\space K^{-1}\times15\space K $
$ Q = 0.2\times400\times15=1200\space J = 1.20\times 10^{3}\space J $
# Answer: B. $ 1.20\times 10^{3}\space J $

### Question 23
# Explanation:
## Step1: Recall lever equilibrium: $ \text{Load}\times\text{Load Arm}=\text{Effort}\times\text{Effort Arm} $
Load $ L = 120\space N $, Load Arm $ d_L = 2\space m $, Effort Arm $ d_E=8\space m $
## Step2: Solve for Effort $ E $
$ E=\frac{L\times d_L}{d_E} $
Substitute values: $ E=\frac{120\times2}{8}=\frac{240}{8} = 30\space N $
# Answer: B. 30 N

### Question 24
# Brief Explanations:
Pascal's principle is applied in hydraulic press (uses fluid pressure transmission). Lift pump (A) uses atmospheric pressure. Force pump (B) is for pumping, not Pascal. Syringe (D) is for injection, not based on Pascal's principle. Hydraulic press (C) uses Pascal's principle.
# Answer: C. Hydraulic press

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

Question 19

Step1: Recall Gay - Lussac's Law (constant volume, \( \frac{P_1}{T_1}=\frac{P_2}{T_2} \), \( T \) in Kelvin)

Step2: Solve for \( P_2 \)

Answer:

Question 20