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The meterstick shown to the right is 100 cm long. It is free to pivot around its

ID: 1474826 • Letter: T

Question

The meterstick shown to the right is 100 cm long. It is free to pivot around its center of gravity (CG), which is at the 50-cm mark. There is a 23.0-N block hanging from the 80-cm mark. Decide where each of the other blocks should be placed, one at a time, to balance out the 23.0-N block. At what mark on the meter stick would you place a 16.0-N block to balance the 23.0-N block? (in cm)

At what mark on the meter stick would you place a 44.0-N block to balance the 23.0-N block? (in cm)

20 30 40 50 60 70 80 90 23.0 N 16.0 N 44.0 N

Explanation / Answer

equating torque equations about COG

23*30 = 44*A + 16 * B

690 =  44*A + 16 * B

let A = 10 i.e. add 44 to 40 mark

690-440 = 16 B

B=15.625

that means apply 16N at 34.375 mark

now if only 16 newton is used

16*x = 23*30

x=43.125

that is apply 16 N at 6.875 mark

now if only 44 newton is used

44*x = 23*30

x=15.6818181818

that is apply 44 N at 34.3181818182 mark