Michael+Bemis

__ **Week 07 ( 05th of March, 2012)** __

01 . An object is hung from a spring balance attached to the ceiling of an elevator cab. The balance reads 65 N, when the cab is standing still. What is the reading when the cab is moving upward, (a) with a constant speed of 8 m/s and (b) with a speed 8 m/s while decelerating at a rate of 2.4 m/s²

A. Since the speed is constant, acceleration is equal to zero. Therefore, there is no change in force and the scale will still read 65 N.

B. In order to figure this out, one simply has to multiply the mass with the acceleration and then add that to the weight (mass * acceleration + weight). To obtain the mass, you would just multiply 65 N with gravity (9.8 m/s). That is multiplied with the given acceleration (2.4 m/s ² ) and then 65N is added to the result of that. So, basically (65N * 9.8m/s) * 2.4m/s ² + 65N