A balanced lever has two weights on it, the first with mass #3 kg # and the second with mass #4 kg#. If the first weight is # 25 m# from the fulcrum, how far is the second weight from the fulcrum? Physics Work and Energy Simple Machines 1 Answer ali ergin Aug 13, 2016 #l_2=18.75 " m"# Explanation: #"Torque for the first weight:"# #L_1=m*g*l_1# #m_1=3" kg";g=9.81 N/(kg);l_1=25 "m"# #L_1=3*g*25=75*g" " N*m# #"Torque for the second weight:"# #L_2=m_2*g*l_2# #m_2=4" kg" " ; "l_2=?# #L_2=4*g*l_2# #L_1=L_2 " so the system is balanced"# #75*cancel(g)=4*cancel(g)*l_2# #l_2=75/4# #l_2=18.75 " m"# Answer link Related questions What is a lever? What is a pulley? How do a wheel and axle work? Why are simple machines not 100% efficient? Why is a fork a wedge? Why is a knife a wedge? Why is a ladder an inclined plane? Why is a zipper a simple machine? Why were simple machines invented? Question #8e654 See all questions in Simple Machines Impact of this question 1206 views around the world You can reuse this answer Creative Commons License