A balanced lever has two weights on it, the first with mass #5 kg # and the second with mass #35 kg#. If the first weight is # 9 m# from the fulcrum, how far is the second weight from the fulcrum?

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Answer 1 · 2016-12-12T21:22:22

#= 1.29m (3s.f.) #

use turning moments:

#M_1 * D_1 = M_2 * D_2#

(#M# being mass of weight on lever, #D# being distance from fulcrum)

#M_1 = 5kg#
#M_2 = 35kg#

#D_1 = 9m#

find #D_2#:

#M_1 * D_1 = 5 * 9 = 45#
#M_2 * D_2 = 35 * D_2 = 45#

#D_2 = (45/35) m#

#= (9/7)m#

#= 1.29m (3s.f.) #