Download Pioneer Science Worksheet

 MAY 2014
PART 1
PART 1
Circle the best answer. 1. It is often thought that heat and temperature is the same thing. Although related to each other, heat and temperature have different concepts. The following are true about temperature except: A. Temperature is the measure of the average energy of molecular motion in a substance. B. Temperature is also known as thermal energy. C. Temperature does not depend on the size or type of object. D. Heat will increase or decrease temperature. 2. Heat can be transferred from one place to another. Which of the following is/are methods of heat transfer? I.
Conduction. II.
Radiation. III.
Convection. A. III only. C. II and III only. PIONEER SCIENCE
WORKSHEET
3. Jesse loves learning about heat and temperature. One hot day, she took 2 glasses of water and wrapped one in white paper and the other with black paper. She filled both glasses with the same amount of water. She left both glasses in the sun for a couple of hours and then returned to measure the temperature of the water in each glass. After measuring the temperatures of the water, Jesse found the water in the glass with the black paper around it, hotter than the other. Which of the following conclusions can be made from the information provided? A. Darker surfaces absorb less heat than lighter surfaces. B. Lighter surfaces absorb more heat than darker surfaces. C. Lighter surfaces reflect more light than darker surfaces. D. Dark surfaces reflect more light than lighter surfaces. B. I and II only. D. All of the above. 1 PART 2
Answer the questions in the spaces provided. 4. Michael conducted the experiment below to understand how heat causes atoms and molecules to move faster. b. What can be inferred from the experiment? Bowl A Bowl B Michael prepared 2 clear bowls and red food colouring. He filled Bowl A with 20 ml of cold tap water and Bowl B with 20 ml of boiling hot water from the kettle. When the water was still, he put a drop of food colouring into the center of each bowl and observed what happened. a. What do you think Michael observed in each bowl? ____________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ c. What can be concluded from the experiment? ___________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ d. Which object contains the most heat, a boiling pot of water or a gigantic iceberg? Explain. ___________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ 2 Answer Scheme
1. B. Temperature is also known as thermal energy. SMART TIPS: Temperature is not energy, but a measure of it. Heat is energy. Heat will always move from higher to lower temperatures. 2. D. All of the above. SMART TIPS: Heat can be transferred from one place to another by three methods: conduction in solids, convection of fluids (liquids or gases), and radiation through anything that will allow radiation to pass. The method used to transfer heat is usually the one that is the most efficient. Conduction is the movement of heat through a substance by the collision of molecules. Convection occurs when warmer areas of a liquid or gas rise to cooler areas in the liquid or gas. Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object. 3. C. Lighter surfaces reflect more light than darker surfaces. SMART TIPS: Dark surfaces such as the black paper absorb more light and heat than the lighter ones such as the white paper. After measuring the temperatures of the water, the glass with the black paper around it should be hotter than the other. Lighter surfaces reflect more light, that's why people where lighter colored clothes in the summer, it keeps them cooler. Answer
Scheme
4. a. The food colouring in Bowl B dispersed faster as compared to the food colouring in Bowl A. b. As the water molecules bumped into the food colour molecules, the food colour will move around. Since the water molecules in Bowl B are moving faster, they will bump into the food colour harder and more frequently causing it to spread more quickly than the food colour in the cold water. c. Heat is the energy an object has because of movement of its atoms and molecules which are continuously jiggling moving around, hitting each other and other objects. When we add energy to an object, its atoms and molecules move faster increasing its energy of motion or heat. Even when objects which are very cold have some energy because their atoms are still moving. d. The iceberg contains more heat than a boiling pot of water. The mass, not just temperature, is an important consideration in determining the heat (energy) content of an object. The total heat content in 500ml of boiling water in a teapot can be approximated by determining how much energy would be removed in order to cool it to absolute zero (about -­‐273oC.). Although the boiling water has a relatively high temperature, it contains relatively little heat energy. Suppose a you were to cool a 1,000,000 ton iceberg (109kg) to absolute zero. While the iceberg is relatively cold (low temperature) it contains an enormous amount of heat energy relative to the boiling water in the teapot. 3