A load weighing 10 kg is lifted up using a system of movable and fixed blocks. Determine the acceleration

A load weighing 10 kg is lifted up using a system of movable and fixed blocks. Determine the acceleration of the load if a force of 60 N is applied to the end of the thread thrown over the stationary block. The mass of the threads and blocks is neglected.

m = 10 kg.

g = 10 m / s2.

F = 60 N.

a -?

Since the load is lifted on a movable block, then Newton’s 2 law for the load will have the form: m * a = 2 * T – Ft, where T is the tension force of the rope, Ft is the gravity of the load.

Since 2 tension forces of the rope act on the movable block, and the stationary block only changes the direction of the force action, then T = F.

m * a = 2 * F – Fт.

a = (2 * F – Ft) / m.

The force of gravity is determined by the formula: Ft = m * g.

a = (2 * F – m * g) / m.

a = (2 * 60 N – 10 kg * 10 m / s2) / 10 kg = 2 m / s2.

Answer: the load rises with acceleration a = 2 m / s2.