Question

A 4.25 kg block rest on a horizontal tabletop. A cord is attached to this block, the cord passing

over a pulley at the edge of the table. At the end of the cord is hung another block weighing 7

kg. Determine the tension in the cord.

Answer 1

For the lighter block m and heavier one M write equations for forces acting on them by Newton's second law:

$$m:T=ma,\\M: -Ma=-Mg+T,\\\space\\ a=\dfrac{M}{M+m}g=6.1\text{ m/s}^2,\\\space\\ T=25.9\text{ N}.$$