Which best describes a mixture? It has a single composition, and it has a set of characteristics that does not change. It can have different compositions, but it has a set of characteristics that does not change. It has a single composition, but it has a set of characteristics that does change. It can have different compositions, and it has a set of characteristics that does change.

option 4 - it can have different compositions, and it has a set of characteristics that change.

yes sir It can have different compositions, and it has a set of characteristics that does change.

thank you to the man/woman above me

Explanation:

its D

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j