Physic Labs

Problem 1

Masses m1=2m_1=2 kg and m2=3m_2=3 kg hang from the ends of a light inextensible string passing over a fixed frictionless pulley of negligible radius. The system is released from rest and the string remains taut. Take g=10g=10 m/s2^2 and choose each mass's direction of motion as positive. (a) Determine the direction and acceleration of each mass. (b) Find the string tension. (c) Find their speed after moving s=0.80s=0.80 m from rest, and check it by energy conservation.
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a=(m2−m1)gm1+m2=2.0 m/s2a=\frac{(m_2-m_1)g}{m_1+m_2}=2.0\ \mathrm{m/s^2}
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Add the equations to eliminate tension, an internal interaction between the two masses. Substitution gives acceleration 2.02.0 m/s2^2 in the chosen directions.