State Newton's laws and force terms

Block A of mass $4,1$ kg is connected to block B of mass $2,3$ kg by a light inextensible string passing over a frictionless pulley. Block A is at rest on a rough horizontal table and block B hangs vertically, as shown in the diagram below.

A force F of magnitude $49$ N is applied on block A at an angle of $50°$ to the horizontal, causing block A to accelerate TO THE LEFT from rest along the table.

The coefficient of kinetic friction between the surface of the table and block A is $0,35$.

In an experiment, a crate of mass $8,5$ kg, lying stationary on a rough horizontal table, is connected to a mass hanger by means of a light inextensible string passing over a frictionless pulley, as shown in the diagram below. Mass pieces are added to the mass hanger and the acceleration of the crate is measured. The experiment is repeated several times by adding different masses to increase the hanging mass each time.

Ignore the effects of air friction.

The results obtained were used to draw the sketch graph below.

Two blocks, $\mathbf{A}$, of mass $4$ kg, and $\mathbf{B}$, of mass $9$ kg, are connected by a light inextensible string. The blocks are held at rest on a plane which is inclined at an angle of $35°$ with the horizontal.

A constant force, $\mathbf{F}$, acting parallel to the plane, is applied to block $\mathbf{B}$, as shown in the diagram below. The blocks now accelerate up the plane at $2$ m·s${}^{-2}$.

Block A of mass m is connected to block B of mass $7,5$ kg by a light inextensible rope passing over a frictionless pulley. Block B is initially held at a height of $1,5$ m above the ground, while block A is initially stationary on the ground, as shown in the diagram below.

When block B is released, it moves vertically downwards and strikes the ground with a velocity of $3,41$ m·s${}^{-1}$.

Ignore the effects of friction.