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

$2.4 \frac{m}{s^{2}}$ in the upward direction.
The upward normal force on you from the scale is (77 kg)(g) = 754.6 N. Apply Newton’s second law to your body. Choose up to be the positive direction. $$\Sigma F=F_N – mg = ma$$ $$a = \frac{ F_N-mg}{m} =\frac{754.6 N-(62 kg)(9.80 \frac{m}{s^{2}})}{62 kg} \approx 2.4 \frac{m}{s^{2}}$$ The answer is rounded to 2 significant figures. The positive sign confirms that the acceleration is upward.