What are examples of mechanical waves

If you have a bowl with six apples and you take away four, how many do you have? anyone take a guess and post it. lol getting rid of my account might as well do it with some fun

Fill in the blank. the number of each type of element in the compound (other than 1) is represented by a small number to the right of the element symbol.

Suppose a diode consists of a cylindrical cathode with a radius of 6.200×10^−2 cm , mounted coaxially within a cylindrical anode with a radius of 0.5580 cm . the potential difference between the anode and cathode is 260 v . an electron leaves the surface of the cathode with zero initial speed (v initial=0). find its speed vfinal when it strikes the anode.