A body with a mass of m = 2 kg moves according to the law: x = 64 · t – 4 · t ^ 2 Find the force acting on the body.

Let a body with a mass of m = 2 kg move according to the law: x = 64 · t – 4 · t². Comparing this equality with the equation of uniformly accelerated rectilinear motion of a body in general form x = vо ∙ t + a ∙ t² / 2, where x is the coordinate of the body at time t, vо is the initial speed of movement, a is the acceleration of motion, we determine that vо = 64 m / s, a / 2 = – 4 m / s² or a = – 8 m / s². According to Newton’s 2 law, the force acting on the body is directly proportional to the acceleration: F = m ∙ a. Substitute the values ​​of physical quantities in the calculation formula and find the value of the force acting on the body:

F = 2 kg ∙ (- 8) m / s²;

F = – 16 N.

Answer: – 16 N – the value of the force acting on the body.