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A seesaw made of a plank of mass 10.0 kg and length 3.00 m is balanced on a fulcrum 1.00 m from one end of the plank. A 20.0-kg mass rests on the end of the plank nearest the fulcrum. What mass must be on the other end if the plank remains balanced?

2 Answers

6 votes

Answer:

The mass at the other end is 7.5 kg.

Step-by-step explanation:

Let the mass is m.

Take the moments about the fulcrum.

20 x 1 = 10 x 0.5 + m x 2

20 = 5 + 2 m

2 m = 15

m = 7.5 kg

A seesaw made of a plank of mass 10.0 kg and length 3.00 m is balanced on a fulcrum-example-1
6 votes

Answer:

7.5 kg

Step-by-step explanation:

We are given that


m_1=10 kg

Length of plank, l=3 m

Distance of fulcrum from one end of the plank=1 m


m_2=20 kg

We have to find the mass must be on the other end if the plank remains balanced.

Let m be the mass must be on the other end if the plank remains balanced.

In balance condition


20* 1=10* (1.5-1)+m* (1.5+0.5)


20=10(0.5)+2m


20=5+2m


2m=20-5=15


\implies m=(15)/(2)


m=7.5 kg

Hence, mass 7.5 kg must be on the other end if the plank remains balanced.

User Dan Alexander
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