Blue litmus paper is used to determine the acidity of a compound. When litmus paper detects hydrogen ions (H+), the paper turns red. Which solution will leave the blue litmus unchanged in color? hydrochloric acid (HCI) hydrobromic acid (HBr) B C sodium hydroxide (NaOH) sodium chloride salt (NaCl) A. Hydrochloric acid (HCI)
B. Hydrobromic acid (HBr)
C. sodium hydroxide (NaOH)
D. sodium chloride (NaCI)​

Bases Do not Change the Color of Blue Litmus.

I'd go with Option C.

Sodium Hydroxide.

your answer would be a. 12.5 kg

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