Dopamine is .a.  a brain chemical linked to addiction b. a chemical found in most addicting substances c. a toxic substance found in the body of most addicts d. a substance in alcohol that causes impaired judgment

substance A

Explanation:

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer