Metals are usually more dense than wood. pick the statement below which accurately compares metals to wood. metals have less mass per unit volume than wood.
metals have more mass per unit volume than wood.
metal and wood have the same mass per unit volume.

Metals have more mass per unit of volume than wood.

Explanation:

Density is defined as the amount of matter contained in a unit of volume. A material that is denser than another will therefore have more mass per unit of volume.

The density of a body can affect buoyancy, bodies with low enough densities can float in fluids. For example wood can float in water while metals can't.

i think the answer is b

russian is not my first language, so i'm afraid i can't write out an answer in russian, but hopefully you can find a way to do so. here's my best translation of the problem: you're given a plot of a particle's position in one-dimensional space over time, and you're asked to find either the total distance traveled by the particle after 6 seconds had elapsed, or the total displacement of the particle after 6 seconds.

if you want the total distance traveled, you would first need to determine the particle's velocity as a function of time, then integrate that over the 6-second interval. we know the position function is quadratic with roots at 0 and 6, so we have

where is unknown. because the position is parabolic, there is symmetry about the midpoint at , and we know that

so that the position function is

which means the velocity is

then the total distance traveled is

so the total distance traveled is 20 m.

on the other hand, if you want to find displacement: the particle starts at and ends at , so its displacement is 0.