With uniformly accelerated motion at an initial speed of 7 m / s, the body covered 25 m

With uniformly accelerated motion at an initial speed of 7 m / s, the body covered 25 m in 4 seconds. What way did the body go in the third second?

Data: uniformly accelerated motion; V0 (initial speed) = 7 m / s; t (duration of movement) = 4 s; S (distance traveled) = 25 m.

1) Define constant acceleration: S = V0 * t + a * t ^ 2/2, whence a = 2 * (S – V0 * t) / t ^ 2 = 2 * (25 – 7 * 4) / 4 ^ 2 = -0.375 m / s2.

2) Calculate the path in the third second: S (3) = S3 – S2 = V0 * t ^ 3 + a * t3 ^ 2/2 – V0 * t2 + a * t2 ^ 2/2 = 7 * 3 + (-0.375 ) * 3 ^ 2/2 – 7 * 2 – (-0.375) * 2 ^ 2/2 = 6.0625 m.

Answer: In the third second, the body covered a distance of 6.0625 m.