Gear

A gear or cogwheel is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part to transmit torque, in most cases with teeth on the one gear being of identical shape, and often also with that shape on the other gear. Two or more gears working in a sequence (train) are called a gear train or, in many cases, a transmission; such gear arrangements can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine. Geared devices can change the speed, torque, and direction of a power source. The most common situation is for a gear to mesh with another gear; however, a gear can also mesh with a linear toothed part, called a rack, thereby producing translation instead of rotation.

The gears in a transmission are analogous to the wheels in a crossed belt pulley system. An advantage of gears is that the teeth of a gear prevent slippage.

When two gears mesh, and one gear is bigger than the other (even though the size of the teeth must match), a mechanical advantage is produced, with the rotational speeds and the torques of the two gears differing in an inverse relationship.

Happy Meal

A "Happy Meal" is a form of kids' meal specifically marketed at children, sold at the fast-food chain McDonald's since June 1977. A toy is included with the food, both of which are usually contained in a box or paper bag with the McDonald's logo. The packaging and toy are frequently part of a marketing tie-in to an existing television show, film, or toy brand.

Product description

The Happy Meal contains a main item (typically a hamburger, cheeseburger, or small serving of Chicken McNuggets), a side item (french fries, apple slices, or a salad in some areas), and a drink (milk, juice, or a soft drink). The choice of items changes from country to country, and may depend on the size of the restaurant.

In some countries, the choices have been expanded to include items such as a grilled cheese sandwich (known as a "Fry Kid"), or more healthy options such as apple slices, a mini snack wrap, salads, or pasta, as one or more of the options.

In most countries, McDonald's has introduced a "healthy option" to the Happy Meal. Children have always been able to choose milk with their Happy Meal and the chain added fruit juice drink instead of a soft drink, and bags of dried fruit (or a whole piece of fruit such as an apple or carrot sticks) in place of fries.