Two objects are connected by a light string passing over a light, frictionless pulley. The 5.00-kg object is released from rest at a point 4.00 m above the floor. Find the speed of the 5.00-kg object when it is 1 meter above the floor. m, = 5.00 kg h= 4.00 m m, = 3.00 kg 4.756 m/s 3.834 m/s С. 3.942 m/s 4.135 m/s 3.384 m/s А. D. В. Е. 4.475 m/s F.

In the pulley system , before the object of mass $m_1=5 kg$ is released from rest , the only energy that exist in the system will be the potential energy of mass $m_1=5 kg$  at height $h_i=4 m$ . When the object is released , this potential energy will be transferred as the kinetic energy of the two masses $m_1=5 kg$ and $m_2=3 kg$ , and the potential energy of the mass $m_2=3 kg$ , when the mass $m_1=5 kg$ reaches the floor as the mass $m_2=3 kg$ will not move anymore at this point.

 The potential energy change ,when the mass $m_1=5 kg$ reaches the height $h_f=1 m$ from the height $h_i=4 m$,that is height difference of $\begin{array}{rcl}∆h& =& h_f-h_i\\ & =& 4m -1m\\ & =& 3m\end{array}$, will be used by both the masses to reach a velocity of v from initial velocity zero and the potential energy change of mass $m_2=3 kg$ as  it reaches an height $h_{2f}=3 m$ from floor, that is height difference of $∆h_2=3m$.