Waves QWC practice question

Question

Student guidance

Expected physics points

• Put equal masses of water at the same starting temperature in identical cans.
• Measure temperature at regular times with the same thermometer or data logger.
• Keep room conditions, can size, water volume and timing the same.
• Repeat measurements and plot temperature against time or compare cooling rates.
• Matt black surfaces are better emitters of infrared radiation than shiny surfaces.
• The black can should transfer energy faster and cool more quickly; shiny surfaces are poorer emitters/reflectors.

Mark scheme points

• Uses equal masses of water at the same starting temperature in identical cans.
• Measures temperature at regular times with the same instrument.
• Controls room conditions, can size, water volume and timing.
• Repeats and plots temperature against time or compares cooling rates.
• Matt black is a better infrared emitter than a shiny surface.
• The black can transfers energy faster; shiny surfaces are poorer emitters or reflectors.

Indicative content

• Put equal masses of water at the same starting temperature in identical cans.
• Measure temperature at regular times with the same thermometer or data logger.
• Keep room conditions, can size, water volume and timing the same.
• Repeat measurements and plot temperature against time or compare cooling rates.
• Matt black surfaces are better emitters of infrared radiation than shiny surfaces.
• The black can should transfer energy faster and cool more quickly; shiny surfaces are poorer emitters/reflectors.