needs for running‚ talking‚ and thinking comes from the food you eat. Energy content is the amount of heat produced by the burning of 1 gram of a substance‚ and is measured in joules per gram (J/g). Usually‚ fat-rich foods like peanuts and cashews provide more energy than just carbohydrates like marshmallows. You can determine the energy content by burning a portion of food and capturing the heat released to a known mass of water in a calorimeter. If you measure the initial and final temperatures
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Discuss why hydrogen bonding is essential for life Throughout biochemistry there are many bonds without which life as it is on earth today would not be possible. One of the most important bonds of these is the hydrogen bond‚ a weak chemical bond that is present in essential biological molecules such as water and polypeptides. A hydrogen bond is defined by Campbell and Reece as occurring when a hydrogen atom is covalently bonded to an electronegative atom but attracted to another electronegative
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of 23 printed pages and 1 blank page. SPA SJF4655/CGW T45720/3 © OCR 2008 [H/103/4250] OCR is an exempt Charity [Turn over 2 EQUATIONS efficiency = useful energy output total energy input energy = mass × specific heat capacity × temperature change energy = mass × specific latent heat fuel energy input = waste energy output + electrical energy output power = voltage × current energy supplied = power × time energy (kilowatt hours) = power (kW) × time (h) wave speed = frequency × wavelength ©
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sure to look over all your notes and be sure to know the following things) 1. Define Temperature‚ thermal energy and heat. 2. A 1.00 x 10²g mass of tungsten at 100°C is placed in 2.00 x 10²g of water at 20.0°C. The mixture reaches equilibrium at 21.6°C. Calculate the specific heat of tungsten. Cw = 4180 J/kg°C C= 171 J/kgOC 3. A certain metal has a specific heat of 400 J / kg oC. It absorbs 8000 J of thermal energy which causes its temperature to raise 10oC. How much mass of the metal
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Hoo Sze Yen Form 4 Experiments Physics SPM 2008 CHAPTER 1: INTRODUCTION TO PHYSICS 1.1 PENDULUM Hypothesis: The longer the length of a simple pendulum‚ the longer the period of oscillation. Aim of the experiment: To investigate how the period of a simple pendulum varies with its length. Variables: Manipulated: The length of the pendulum‚ l Responding: The period of the pendulum‚ T Constant: The mass of the pendulum bob‚ gravitational acceleration Apparatus/Materials: Pendulum bob‚ length
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Questions 1 HKALE 1990 Biology Paper II 1 HKALE 1993 Biology Paper II 1 HKALE 1996 Biology Paper II 1 HKALE 1999 Biology Paper II 1 Suggested Solution 3 HKALE 1990 Biology Paper II 3 HKALE 1993 Biology Paper II 4 HKALE 1996 Biology Paper II 6 Questions HKALE 1990 Biology Paper II 5. (b) Discuss the importance of carbohydrates‚ lipids‚ proteins and roughage in the human diet. (8 marks) Suggested Solution… HKALE 1993 Biology Paper II 6. Based upon its properties‚ discuss
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ΔT. We can assume that the specific heat capacity of water is 4.18 J / (g × °C) and the density of water is 1.00 g/mL. qwater = m × c × ΔT m = mass of water = density x volume = 1 x 26 = 26 grams ΔT = T(mix) - T(water) = 38.9 - 25.3 = 13.6 q(water) = 26 x 13.6 x 4.18 q(water) = 1478 Joules SPECIFIC HEAT: qmetal = -205 J = 15.363 g X c X (27.2 - 100.3 C) c = 0.183 J/gC PART2. Using the formula qmetal = m × c × ΔT‚ calculate the specific heat of the metal. Use the data from
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An intensive property is a bulk property‚ meaning that it is a physical property of a system that does not depend on the system size or the amount of material in the system. Examples of intensive properties are the temperature and the hardness of an object. No matter how small a diamond is cut‚ it maintains its intrinsic hardness. By contrast‚ an extensive property is one that is additive for independent‚ noninteracting subsystems.[1] The property is proportional to the amount of material in the
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3 Question 1 (Marks: 20) On a straight‚ flat section of road‚ a car follows a truck. Initially (t < 0)‚ both are travelling at speed v0 = 90 k.p.h. The truck maintains constant speed throughout. The car is initially 2.0 seconds behind the truck‚ i.e. for t < 0 the car
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of photosynthesis requires water in order to create glucose. The fact that water has an unusually high specific heat capacity makes it a very useful substance for living organisms. Water does not change temperature very easily and therefore minimizes fluctuations in temperature in cells and creates a remarkably constant sea temperature for aquatic organisms. Water has a high latent heat of vaporisation which means that when animals sweat and plants transpire water‚ takes energy from the organism
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