v=v=- v=- π 2vmax Wđ = Wđmax = W 2 v max π Wđ = 3Wt π 1v max Wđ = Wt π Wđ = Wđ = v=0 a = amax a= 3Wt −A -A −A 2 A −A A 2 A A amax a= 2 v= a max v= a= a max v= a=0 v = vmax vmax 2 x v max v max