For a second order reaction, the half-life is equal to:.

Half life = 1 / k[Ao]

Explanation:

From:

1/ [A] = kt + 1/ [Ao]

Isolating t on its own, we have:

kt = 1 / [A] - 1 / [Ao]

t = 1 / [Ao] / k

Re-arranging we have:

t = 1 / k [Ao]

The t represents the t=half life of the second order reaction and the formula can be re-written as:

t1/2 = 1 / k [Ao]

This is so because second order reaction decreases at a much faster rate than zero and first order reactions and there slopes decreases to zero at a much faster rate.

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

3 1/4 %

explanation: