Answer: Wheel and Axle
Both of these work together to form a simple machine. You can't have one without the other.
If you try to turn just the axle itself, then you'll find it takes a lot of work. This is because the inertia of the axle wants to keep the object at rest. Also, you won't have a lot of torque due to the small radius compared to what a doorknob can offer.
Using a doorknob is like putting a (steering) wheel on an axle. This increases the radius and therefore increases the torque. You put in less work into the system and get more out of it.
Answer:
What is the difference between the crust and lithosphere? The crust (whether continental or oceanic) is the thin layer of distinctive chemical composition overlying the ultramafic upper mantle. ... The lithosphere is the rigid outer layer of the Earth required by plate tectonic theory.
Explanation:
Answer is: halogens ans noble gases.
The nonmetals are divided into two categories: reactive nonmetals and noble gases.
Halogen elements are in group 17: fluorine (F), chlorine (Cl), bromine (Br) and iodine (I). They are very reactive and easily form many compounds.
Noble gases are in group 18: helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and radon (Rn). They have very low chemical reactivity.