The equation of motion of a material point along the Ox axis has the form: x = A + Bt + Ct2, where A = 1 m,

The equation of motion of a material point along the Ox axis has the form: x = A + Bt + Ct2, where A = 1 m, B = 3 m / s, C = -0.5 m / s ^. Determine the modulus of the point velocity over the time interval delta t = 5 s. after the start of the countdown?

From this equation, we can find the starting speed, starting position and acceleration.
x0 = 1, V0 = 3, a = -0.5
General form:
x = x0 + V0t + (at ^ 2) / 2
The general acceleration formula is
a = (V-V0) / t
We express the required speed from here:
V = at + V0
We substitute:
V = (- 0.5) * 5 + 3 = 0.5
Answer: about 5 m / s