A body weighing 3 kg is pulled horizontally by the rope with a force of 12 N directed at an angle of 600

A body weighing 3 kg is pulled horizontally by the rope with a force of 12 N directed at an angle of 600 to the horizontal. Determine the acceleration of the body. There is no friction force.

m = 3 kg.

F = 12 N.

∠α = 60 “.

but – ?

Let’s write Newton’s 2 law for a body in vector form: m * a = F, where m is the mass of the body, a is the acceleration of the body, F is the force that acts on the body.

Draw the OX axis in the direction of motion and write Newton’s 2 law for projections onto this axis.

m * a = F * cosα, where ∠α is the angle between the direction of the force and the axis.

The formula for determining the acceleration of a body will be: a = F * cosα / m.

cos60 “= 0.5.

a = 12 N * 0.5 / 3 kg = 2 m / s ^ 2.

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