13. A hole is drilled in a block of wood as shown in the sketch. The hole is 3/4 of the total depth of the wood. The total depth of the block of wood is 13/16 in.
How deep is the hole?
Hole

What’s #16 asking me and how do i solve it?

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

What is an example of static friction