You walk into an elevator, step onto a scale, and push the “up” button. You recall that your normal weight is 625 N. Draw a free-body diagram. (a) When the elevator has an upward acceleration of magnitude 2.50 m/s2, what does the scale read? (b) If you hold a 3.85-kg package by a light vertical string, what will be the tension in this string when the elevator accelerates as in part (a)?

Solution 8E Your normal weight = 625 N Acceleration due to gravity g = 9.80 m/s 2 Therefore, your mass m = 625 N/(9.80 m/s ) 2 m = 63.7 kg 2 (a) The elevator has an upward acceleration of 2.5 m/s . The free body diagram can be drawn as shown below. The elevator has an upward acceleration. Therefore, the net acceleration will be 2 2 2 a net= g + a = 9.80 m/s + 2.50 m/s = 12.3 m/s Your mass is m = 63.7 kg Therefore, when the elevator accelerates up, the...