A box weighing 30 kg is moved along a horizontal plane with a force of 150 N. What is the acceleration

A box weighing 30 kg is moved along a horizontal plane with a force of 150 N. What is the acceleration of the box if the coefficient of friction is 0.4?

m = 30 kg.

g = 9.8 m / s ^ 2.

μ = 0.4.

F = 150 N.

and – ?

Let us write Newton’s 2 law in vector form: m * a = F + Ft + Ftr + N, where m is the body mass, a is the acceleration of the body, F is the force with which the load is pulled, Ft is the force of gravity, Ftr is the friction force, N – surface reaction.

2 Newton’s law in projections: m * a = F – Ftr, Ft = N.

Ftr = μ * N.

Fт = m * g.

m * a = F – μ * m * g.

a = (F – μ * m * g) / m.

a = (150 N – 0.4 * 30 kg * 9.8 m / s ^ 2) / 30 kg = 1.08 m / s ^ 2.

Answer: the body moves with acceleration a = 1.08 m / s ^ 2.