Physic Labs

Problem 1

Two small masses m1=2.0 kgm_1=2.0\,\mathrm{kg} and m2=1.0 kgm_2=1.0\,\mathrm{kg} are joined by a light inextensible string over an ideal pulley. m1m_1 rests on a smooth plane inclined at 30∘30^\circ to horizontal and m2m_2 hangs vertically. The system is released from rest; take g=9.8 m/s2g=9.8\,\mathrm{m/s^2}. (a) Find the acceleration and direction. (b) Find the tension and normal force on m1m_1. (c) Find the distance each mass travels in the first 2.0 s2.0\,\mathrm{s}, assuming the string stays taut.
(m1+m2)a=m2g−m1gsin⁡30∘=0⇒a=0(m_1+m_2)a=m_2g-m_1g\sin30^\circ=0\Rightarrow a=0
problems.proof.analysis

Add the equations to eliminate tension. The right side vanishes, so the system acceleration is zero, consistent with the force comparison.