Question

A hand pushes three identical bricks as shown. System A consists of two bricks stacked together. System B consists of a single brick. System C consists of all three bricks. There is friction between the bricks and the table. The bricks are moving to the left and speeding up. In the spaces provided at right, draw and label separate free-body diagrams for systems A and B. (Ignore vertical forces.) The vector representing the acceleration of system A is shown at right. Draw the acceleration vectors for systems B and C using the same scale. Explain. The vector representing the net force on system A is shown at right. Draw the net force vectors for systems B and C using the same scale. Explain. The vector representing the frictional forces on systems A and B are shown below. Draw the remaining force vectors using the same scale. Explain how you knew to draw the force vectors as you did. A hand now pushes the same bricks to the right with the force of the same magnitude as in part a. The bricks are moving to the right and speeding up. Systems A, B, and C are the same as in the previous case. As before, there is friction between the bricks and the table. In the spaces provided at right, draw and label separate free-body diagrams for systems A and B. (Ignore vertical forces.) Using the same scales as in part a, draw the acceleration and net force vectors for systems A, B and C. Explain. Using the same scale as in part a, draw the force vectors using the same scale. Explain how you knew to draw the force vectors as you did. Do you agree or disagree with the statement below? Explain. "The force by the hand pushing on system C from the left or from the right are the same. Thus the internal forces are the same in both cases."

Answer 1

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Net force on C BA He rCe O dueんし Similar t for 3 c FBD syskm & ne TB Net force on A li.Accelenaion of A Ne^ force on C Acceleroよonよ

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