Which velocity-time graph matches this position-time graph?

The best answer is (a) which is universal law is in effect at all times. it is constantly at play in everything we do and governs our lives. it is also important to note that universal law applies to not only everything on earth, but everything in the universe as well, which is another reason why it is in effect at all times.

Chromium  +  hydrogen sulfate  =  chromium(iii) sulfate  +  hydrogenso then it will be  a. cr + h2so4? cr2(so4)3 + h2 

Answerporcelain

Average net force: ∑f = fapp + fgrav = 8.20 + (-9.81m/s²)(0.500 kg)           = 3.295 n          = 3.30 nvelocity of object∑f = maa = ∑f / m = 3.295 n / 0.500 kg = 6.59 m/s²v² = v₀² + 2adv = √(v₀² + 2ad)v = √[ 0² + 2(6.59m/s²)(1.50m) ]v = 4.45 m/s