## Physics: Principles with Applications (7th Edition)

The maximum tension in the sheets is (58 kg)(g) = 568.4 N. Apply Newton’s second law to the thief. Choose up to be the positive direction. $$\Sigma F=F_t – mg = ma$$ $$a = \frac{ F_t-mg}{m} =\frac{568.4 N-(75 kg)(9.80 \frac{m}{s^{2}})}{75 kg} \approx -2.2 \frac{m}{s^{2}}$$ The answer is rounded to 2 significant figures. The negative sign confirms that the acceleration is downward. The weight exceeds the tension, so the thief is moving downward vertically, and speeding up.