Determine the modulus of the force that must be applied in the horizontal direction to a body with a mass of 1 kg

Determine the modulus of the force that must be applied in the horizontal direction to a body with a mass of 1 kg, motionlessly lying on a horizontal surface, so that after a time interval of 2 s, it acquires a speed of 2 m / s.

Given:

m = 1 kg – body weight;

t = 2 seconds;

v = 2 m / s is the speed that the body must acquire during the time t;

F friction = 3 Newton – friction force modulus.

It is required to determine the force F (Newton), which must be applied to the body in order for it to reach the speed v in time t.

Let us find the acceleration that the body must have in order to develop speed:

a = v / t = 2/2 = 1 m / s ^ 2.

According to Newton’s second law:

F – Ftr = m * a;

F = m * a + Ftr = 1 * 1 + 3 = 2 + 3 = 5 Newton.

Answer: a force of 5 Newton must be applied to the body.