Unit 1
Activity
1.1.3 Gears - VEX
You do not have to look far to see gears. You might not think of an object such as a computer as having a lot of moving parts, but the CD tray on your computer is likely controlled by gears. A traditional watch is full of gears. The watch has one source of power or input that must move multiple hands continuously and at different speeds. Some watches also keep track of the day of the month. This may be low-tech by today’s standards, but imagine the challenge of choosing just the right gears to keep a watch synchronized. In a watch the gears are used to manipulate rotational speed. Gears are also used in many applications to control torque and rotational direction.
Activity 1.1.4 Pulley Drives and Sprockets
Pulleys and sprockets achieve the same tasks as gears by transferring power through rotary motion. Depending on how pulleys and sprockets are applied, speed, direction, and torque can be modified within the system. Pulleys and sprockets are both used in everyday machines ranging from industrial applications to moving printer heads within a desktop printer. Typically, belts and pulleys are easier to manufacture, lighter weight, and less expensive to purchase than sprockets and chains. Although chains and sprockets are more difficult to manufacture and often noisier, they have the advantage of not slipping as easily and tend to be more durable then a belt and pulley system.
Activity 1.1.5 Gears, Pulley Drives, and Sprockets Practice Problems
Answer the following questions regarding gear, pulley, and sprocket systems. Each question requires proper illustration and annotation including labeling of forces, distances, direction, and unknown values. Illustrations should consist of basic top view assembly sketches rather than realistic pictorials. Be sure to document all solution steps and proper units. Remember: counted teeth have infinite digits, and assume all other measurements contain three (3) significant digits.
Activity 1.2.1 Energy Sources
A. 1.2.4 Circuit Calculation
Regardless of circuit complexity, circuit designers as well as users need to be able to apply basic electrical theories to circuits in order to verify safe operation and troubleshoot unexpected circuit failure. In this activity you will gain experience applying Ohm’s law and Kirchhoff’s voltage and current laws to circuits in order to gain understanding of circuit requirements and relationships between voltage, current, and resistance.
Activity 1.2.3 Electrical Circuits – Physical
Since the late 1800s, engineers have designed systems to utilize electrical energy due to its ability to be converted, stored, transmitted, and reconverted efficiently into other forms of energy. In the 21st century, electrical energy production, distribution, and application have become consumer-driven. Today’s consumer utilizes electrical energy in all aspects of life, from cell phones and computers to refrigeration and heating and cooling systems, and even transportation. Electrical energy, depending on geographic location, is converted from mechanical energy, chemical energy, light energy, and thermal energy before it reaches the consumer.
1.2.4 Circuit Calculation
Regardless of circuit complexity, circuit designers as well as users need to be able to apply basic electrical theories to circuits in order to verify safe operation and troubleshoot unexpected circuit failure. In this activity you will gain experience applying Ohm’s law and Kirchhoff’s voltage and current laws to circuits in order to gain understanding of circuit requirements and relationships between voltage, current, and resistance.
Activity 1.3.3 Thermodynamics
Think back to the last time someone complained about a door being left open. What did you notice about the temperature within the room as a result of the open door? In Activity 1.3.3 you will investigate the effects of work, thermo energy, and energy on a system, as in the case of the room with the door left open.