A 530-kg I-beam that is 4.6 m long has one end attached to a vertical wall. The I-beam is allowed to pivot up and down about the attachment location. A long cable is then attached to the other end of the I-beam and hoisted vertically so the I-beam is exactly parallel with the ground. The tension in the cable is
A) 5300 N.
B) 0 N.
C) 2600 N.
D) 4500 N.

Question

Quizplus · Accepted Answer

The tension in the cable must balance the weight of the I-beam to keep it parallel to the ground. The weight of the I-beam is 530 kg * 9.8 m/s² = 5194 N. Since the cable is attached at the end, the tension is half of the weight, so 5194 N / 2 ≈ 2600 N.

A 530-Kg I-Beam That Is 4