6. Intro to Forces (Dynamics)

A 3-kg box of junk is being lowered on a string at a constant speed. What is the tension in the string?

(II) A 20.0-kg box rests on a table.

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(b) A 10.0‑kg box is placed on top of the 20.0-kg box, as shown in Fig. 4–36. Determine the normal force that the table exerts on the 20.0-kg box and the normal force that the 20.0-kg box exerts on the 10.0-kg box.