A complex machine is a machine made up of two or more simple machines that make your work easier to do. There are six simple machines from which all complex machines are made. They include: The lever. The inclined plane
Explanation:
Given that,
The range of human hearing extends from approximately 20 Hz to 20 000 Hz. We need to find the wavelengths of these extremes when the speed of sound in air is equal to 338 m/s.
Speed of any wave is given by :

is wavelength of wave
If f = 20 Hz

If f = 20000 Hz

The smallest wavelength that can be heard is 0.0169 m and the longest wavelength that can be heard is 16.9 m.
Yes, i believe they absolutely should make radon testing mandatory.
Being exposeed to radon substance for a certain period of time will dramatically increase children's chance in developing lung cancer.
The thing is, Radon is a type of substance that does not have a visual form, taste, or smell which make proper testing is the only way to detect them.
An imbalance of electrons causes an object to be charged. A charged substance is one that has a net charge that is not zero. If the number of protons and that of electrons is equal in an object, the object is not neutral, but it has zero charge. Loss or gain of electrons determine the charge of an object, when an object loses electrons it becomes positively charged, but when it gains electrons it becomes negatively charged.
answer: (description atoms) are made of tiny particles called protons, neutrons and electrons.
Explanation: