post 7 thank you for the explanation. i understand now difference of consant and nonconstant acceleration. question in post 1 isn't good to find nonconstant acceleration because graph is describing velocity and i need to know nonconstant velocity to find the nonconstant acceleration.

if i need distance, i find area under curve of velocity graph and if i need acceleration i find slope of velocity graph. this is my understand and i think it make sense since \(\displaystyle v = \frac{dx}{dt}\) and \(\displaystyle a = \frac{dv}{dt}\)

i'm sorry to say this, but i have never seen your formulas in my physics class. in physics class we use

\(\displaystyle v = v_0 + at\)

\(\displaystyle x = x_0 + v_0t + 0.5at^2\)

\(\displaystyle v^2 = v_0^2 + 2ax - 2ax_0\)

physics book use this

\(\displaystyle v = v_0 + at\)

\(\displaystyle x = x_0 + v_0t + \frac{1}{2}at^2\)

\(\displaystyle v^2 = v_0^2 + 2a(x - x_0)\)

\(\displaystyle \bar{v} = \frac{v + v_0}{2}\)

i'm sure this is physics problem, not calculus. i'll show a picture next time of the formulas notation and question

i'm also confused at post 2, he say we need to know how exactly acceleration varies with time to answer the question, why he didn't say we need to know how exactly velocity varies with time time instead. may got confused?!

i'm an artist. i draw people anime nature any thing. i also enter a house and i can design a similar small version of it. i'm currently studying mechanical engineer major and chemical engineering minor. i'm very bad in beginning math courses like algebra. this make struggling in main courses. this is why i memorizing to solve question without understand any math

i just want to understand three things. basic idea of algebra, basic idea of physics, and basic idea of calculus