A 5.0-kg mass is attached to the ceiling of an elevator by a rope whose mass is negligible. What force does the mass exert on the rope when the elevator has an acceleration of 4.0 m/s2 upward?
A. 69 N downward
B. 29 N downward
C. 49 N downward
D. 20 N downward
E. 19 N downward
Answer: A
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Fill in the blank(s) with the appropriate word(s).
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