The train, starting to move, within 10 s developed a speed of 15 m / s, moving uniformly accelerated.

The train, starting to move, within 10 s developed a speed of 15 m / s, moving uniformly accelerated. During the next 5 s, the train was moving evenly. Determine: 1) the acceleration of the train in the first 10 s; 2) the distance traveled by the train: a) in 10 s; b) for the next 5s; c) for the entire time of movement.

Data: t1 (first time) = 10 s; V0 (initial speed) = 0 m / s; V1 (speed reached in 10 s; constant speed on the second section of the path) = 15 m / s; t2 (second time) = 5 s.

1) Acceleration in the first section: a = (V – V0) / t = (15 – 0) / 10 = 1.5 m / s2.

2a) The path for the first 10 s of accelerated movement: S1 = V0 * t + a * t ^ 2/2 = 0 * 10 + 1.5 * 10 ^ 2/2 = 75 m.

2b) The path in 5 s of uniform movement: S2 = V1 * t ^ 2 = 15 * 5 = 75 m.

2c) Path for all time: S = S1 + S2 = 75 + 75 = 150 m.