500 kg rock tension 2000 N density

500 kg rock tension 2000 N density

 

 

A 500 kg rock whose density is unknown is suspended by a string

such that 1⁄2 of the rock’s volume is under water.

The tension is 2000 N. Find the density of the rock.

 

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[rock의 부피의 1/2이 물에 잠긴 조건]

T = mg[1 – (ρ_w / 2ρ_r)]

( 참고 https://ywpop.tistory.com/24029 )

 

 

 

1 – (ρ_w / 2ρ_r) = T / mg

 

ρ_w / 2ρ_r = 1 – (T / mg)

 

ρ_r = ρ_w / 2(1 – (T / mg))

= 1000 / [2(1 – (2000 / (500×9.8)))]

= 844.8 kg/m3

 

 

 

답: 845 kg/m3

 

 

 

 

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