Chapter 4.2 Questions
What is input and output?
Input: everything you do to make the machine work Output: what machines does for you
What is a machine?
A machine is a device with moving parts that work together to accomplish a task
What is a simple machine?
A simple machine is a mechanical device that accomplishes a task with only one movement. simple machines work with forces; input force and output force
What is mechanical advantage?
MA= fo/fi (mechanical advantage equals output force divided by input force) The mechanical advantage of a machine is the ratio of the output force to the input force. A mechanical advantage larger than 1 that means that the output force is larger than the input force A mechanical advantage smaller than 1 means that the output force is smaller than the input force
Can the output work of a machine be greater that the input work?
No, the output work of a machine can never be greater than the input work. This is true for all machines
What is a perfect machine?
Perfect machine the output work equals the input work- there are no perfect machines. Friction always converts some of the input work to heat and wear, so the output is always less than the input work. But for well-designed machines friction can be small and assume that the input and the output work are approximately equal. friction can be so insignificant that we can assume that the input and output force are both approximately equal.
What are the parts of a lever?
There are three parts to a lever: 1. Fulcrum, which is the middle part of the lever 2. Input arm, which is the side of the lever where the input force is applied 3.Output arm, which is the end of the lever that applies the output force
List the simple machines, give examples:
Wheel: Axle: Rope: Pulley: Ramp: Lever:
What happens when the fulcrum is in the middle or is not in the middle? And give and example:
When the fulcrum is in the middle the input and output arms are the same, so when the fulcrum is not centered both arms are not equal the side with the longer arm has a smaller force EX: if the input arm is 10 times longer than the output arm, the output force is 10 greater than the input force
