An object of mass hangs at the end of a rope. Find its acceleration when the tension in the rope is .
Explanation
|\mathrm{W}-\mathrm{T}|=\mathrm{ma} \
|200 \times 9.8-2000|=200 \mathrm{a} \
\mathrm{a}=\frac{|1960-2000|}{200} \
\mathrm{a}=\frac{40}{200}=0.2 \mathrm{~m} / \mathrm{s}^2, \text { B } \
\text { Note: if we use } \mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2, \text { we obtain } \
\mathrm{W}-\mathrm{T}=\mathrm{ma} \
\mathrm{mg}-\mathrm{T}=\mathrm{ma} \
200 \times 10-2000=\mathrm{ma} \
0=200 \mathrm{a} \
\mathrm{a}=0 \mathrm{~m} / \mathrm{s}^2
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