A body weighing 0.5 kg begins to move under the action of 35H, which will be equal to its speed in 4 seconds.

Initial data: m (body weight) = 0.5 kg; F (the force under which the body began to move) = 35 N; t (duration of body movement) = 4 s; V0 (initial velocity of the body) = 0 m / s.

1) Determine the acceleration with which the body began to move: F = m * a; a = F / m = 35 / 0.5 = 70 m / s ^ 2.

2) Let’s calculate the speed of the body in 4 seconds: V = V0 + a * t = 0 + a * t = 70 * 4 = 280 m / s.

Answer: The speed of the body in 4 seconds will be 280 m / s.