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BTEC Level 3 Applied Science. Some months have 30 days, some months have 31 days. How many months have 28 days? If a doctor gives you 3 pills and tells you to take one pill every half hour, how long would it be before all the pills are taken?
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Some months have 30 days, some months have 31 days. How many months have 28 days? • If a doctor gives you 3 pills and tells you to take one pill every half hour, how long would it be before all the pills are taken? • I went to bed at eight o'clock in the evening and wound up my clock and set the alarm to sound at nine o'clock in the morning. How many hours sleep would I get before being woken by the alarm?
Divide 30 by half and add ten. What do you get? • A farmer had 17 sheep and all but 9 die. How many are left? • If you had only one match and entered a COLD and DARK room, where there was an oil heater, an oil lamp and a candle, which would you light first? • If you take 2 apples from 3 apples, what do you have? • 9. An assistant in a butcher's shop is 5'10" tall. What does he weigh?
What do you put in a toaster? Say "Silk" 5 times, now spell "Silk". What do cows drink? If a red house is made of red bricks and a blue house is made of blue bricks, what is a green house made of? A plane crashes on the Canadian - US border. Where would you bury the survivors? 14. If the hour hand on a clock moves 1/60th of a degree every minute, how many degrees will it move in an hour?
15. Johnny's mother has 3 kids, one is named April, one is named May. What is the other one named? 16. In a one storey house the floor is blue and the walls and ceiling are white. What colour are the stairs? 17. A cowboy rode into town on Friday, spent the night, and left on Friday. How can this be? 18. I have two coins which add up to 15 pence and one of the coins is NOT a 10 pence piece. What are the two coins? 19. If a rooster laid an egg on the apex of a slanted barn roof, which way would the egg roll, left or right?
1. All of them. Every month has at least 28 days. • 2. 1 hour. If you take a pill at 1 o'clock, then another at 1.30 and the last at 2 o'clock, they will be taken in 1 hour. • 3. 1 hour. It is a wind up alarm clock which cannot discriminate between a.m. and p.m. • 4. 70. Dividing by half is the same as multiplying by 2. • 5. 9 sheep. • 6. The match. Answers
2 apples. You took them remember. Meat. Bread. Water. Glass. 12. You don't bury survivors. Answers
You don't bury survivors. 14. 1 degree. 15. Johnny. 16. There are no stairs. 17 .His horse is called Friday. 18. A 10 pence piece and a 5 pence piece. Only one coin is NOT a 10 pence piece. 19. Roosters don't lay eggs. Answers
Unit 14: Energy Changes, Sources and Applications • Unit 10: Using Science in the Workplace Topics
Know the fundamental concepts associated with energy and its measurement Definitions: work as force × distance moved in direction of force (W = Fd); energy in terms of work; kinetic energy (KE = ½ mv2); potential energy (PE = mgh); elastic potential energy (PEe = ½ kx2); power as the rate of transfer of energy Concepts: principle of the conservation of energy; recognition of energy types as forms of potential or kinetic energies; useful energy, wasted energy and efficiency Quantities and units: energy (joule); power (watt, kilowatt) Unit 14: Energy Changes, Sources and Applications
Be able to investigate how changes of temperature or physical state relate to changes in internal energy Temperature: degree of hotness; temperature scales (Kelvin, Celsius) and fixed points (absolute zero); thermal expansion Energy changes: transfer of energy can cause a rise or fall in temperature or changes of state; calculations, e.g. specific heat capacity (Q = mcΔt), specific latent heat (Q = mL); fusion; vaporisation; condensation; Applications Gases: effect of changing temperature, pressure and volume of a gas; experimental evidence for a gas law eg Charles’ Unit 14: Energy Changes, Sources and Applications
Understand the differences and relationships between different energy-transfer mechanisms Energy-transfer mechanisms: conduction (transfer of kinetic energy between atoms, electrons or molecules); thermal conductivity of solids, liquids and gases; convection (bulk motion of liquids); radiation (absorption, emission and relation to surface properties); Stefan’s law of radiation (W = eσAT4); temperature gradient; applications Relationships: differences between forced and natural convection Unit 14: Energy Changes, Sources and Applications
Understand the properties of electrical energy sources Structure and operating principles of common primary and secondary cells: characteristics, merits and limitations for particular applications; capacity and behaviour under load; ampere-hours, mill ampere-hours; disposal hazards; applications Fuel cells: cells e.g. simple cell, the leclanche dry cell and the lead-acid cell, zinc-air fuel cells (ZAFC), proton exchange membrane or solid polymer, direct methanol fuel cells, recent developments, their prospects and limitations Solar cells: recent developments; their prospects and limitations Unit 14: Energy Changes, Sources and Applications
Energy and its uses are fundamental to any physics course. Indeed, physics can be described as the study of energy. So first of all, let's examine the term energy. • Whenever people such as politicians, businessmen or journalists talk about energy, it is usually in terms of supplying it to industrial and domestic markets, for example as quantities of oil, gas, coal or uranium. These are fuels used throughout the world to supply energy to industrial and domestic markets. There is a huge demand for this energy, because it is used to do work. This includes work to fly planes, to drive cars, to run machinery in factories and homes, to operate televisions, computers, telephones, telecommunication systems. The list goes on! Energy
Let's look at one specific use of the chemical energy stored in oil. A car's engine is able to release this energy from the oil and some of the energy does work to move the car along the road. Unfortunately, the conversion of chemical energy into work is never 100% efficient. Most modern cars have efficiencies below • This problem is due to the very nature of energy-to-work conversions. There is a theoretical limit on the efficiency of a car engine that depends on the high temperature of the burning fuel and the low temperature of the surroundings. Energy
At a basic level energy is either ....................or ________energy. • • Kinetic energy: where movement is taking place. • • Potential energy: regions where electric, magnetic and nuclear forces exist. Regions such as this are called fields. • However different energy names are frequently used for specific situations. We have just looked at the form that is called chemical energy. Energy
The following is a list of different forms of energy together with some details of how the energy is stored. • • Chemical energy: energy can be released when the arrangement of atoms is altered. • • Electrical potential energy: for example, a positive charge is pushed close to another positive charge. This will often be called electrical energy. • • Electromagnetic energy: includes all the waves that travel at the speed of light in a vacuum - gamma rays, X-rays, ultraviolet, light, infrared, microwaves and radio waves. These waves hold their energy in electric and magnetic fields. • • Potential energy: where an object is at a high level. • • Internal energy: the molecules in all objects have random movement and have some potential energy when they are close to one another. This type of energy is often called heat energy. • • Kinetic energy: when an object has speed. • • Nuclear energy: energy can be released by reorganising the protons and neutrons in an atom's nucleus. This form of energy is also known as atomic energy. • • Sound energy: in the movement of atoms. Energy
We can calculate the work done when a force moves using this equation: • Doing work requires energy. Energy is often defined as the ability to do work. • Doing work involves a transfer of energy from one form to another. For example, when you use your muscles to move an object some of the stored energy in your body is transferred to kinetic (movement) energy. Work and energy
The amount of work done tells you how much energy has been transferred from one form to another: Both work and energy have the same unit, the joule (J). Work and energy
If two cars of the same weight drive up the same hill, they do the same amount of work. But what if one car is more powerful than the other? • Although the total energy transferred in reaching the top is the same for both cars, the more powerful car will get there faster. • Power is a measure of how fast work is done, or energy is transferred: Power
If the work rate is not steady, these equations give the average power. • The unit of power is the watt, W. • 1 watt = 1 joule per second Power