7. (10 points) Determine the force $F$ that needs to be applied to the plate to move a load of mass $m=2$ kg, lying on a horizontal smooth surface. All pulleys are smooth and weightless. The acceleration due to gravity $g=10 \mathrm{m} /$ kg.

![](https://cdn.mathpix.com/cropped/2024_05_06_cb5516e3c2a397a958cdg-3.jpg?height=402&width=751&top_left_y=2129&top_left_x=752)
Answer: $20 \mathrm{H}$.

Solution. Let's arrange the forces acting in this system:

![](https://cdn.mathpix.com/cropped/2024_05_06_cb5516e3c2a397a958cdg-4.jpg?height=334&width=617&top_left_y=130&top_left_x=822)

We get: $F=4 T=m g=2 \cdot 10=20 \mathrm{H}$.