Find the lifting force of a 4 kg cork life belt in sea water, if the densitites of cork and sea water are 0.2 × 103 kg / m 3 and 1.03 × 103 kg / m 3 respectively.

Question

Find the lifting force of a 4 kg cork life belt in sea water, if the densitites of cork and sea water are 0.2 × 103 kg / m 3 and 1.03 × 103 kg / m 3 respectively. (A) 163 N (B) 273 N (C) 119 N (D) 298 N

Tardigrade Admin · Accepted Answer

Volume of cork =(4/0.2× 103)m3 Weight of liquid displaced when cork is fully immersed in water =(4/200)× 1.03× 103× 9.8 N Lifting force =(4/200)× 1.03× 103× 9.8-4× 9.8 =201.88-39.2 =163 N

Q. Find the lifting force of a $4 k g$ cork life belt in sea water, if the densitites of cork and sea water are $0.2 \times 1 0^{3} k g / m^{3}$ and $1.03 \times 1 0^{3} k g / m^{3}$ respectively.

163 N

273 N

119 N

298 N

Volume of cork $= \frac{4}{0.2 \times 10 ^{3}} m^{3}$
Weight of liquid displaced when cork is fully immersed in water
$= \frac{4}{200} \times 1.03 \times 10^{3} \times 9.8 N$
Lifting force
$= \frac{4}{200} \times 1.03 \times 10^{3} \times 9.8 - 4 \times 9.8$
$= 201.88 - 39.2$
$= 163 N$

Q. Find the lifting force of a 4kg cork life belt in sea water, if the densitites of cork and sea water are 0.2×103kg/m3 and 1.03×103kg/m3 respectively.