Calculating Density: Answers Explained

Thread starter dinhjeffrey
Start date Apr 24, 2011
Tags

Density

AI Thread Summary

The discussion revolves around calculating density using the formula D=M/V, where a ball's mass is given as 5 kg and its volume as 2.5 x 10^-2 m^3, resulting in a density of 200 kg/m^3. The density of water is noted as 1000 kg/m^3, leading to a difference of 800 kg/m^3 when subtracted. The mass required to achieve this density is calculated to be 20 kg. Finally, using F=ma, the force is determined to be 200 N, confirming the initial calculation despite some confusion over the answer options. The thread concludes with the user affirming the correct answer is indeed 200 N.

Apr 24, 2011

dinhjeffrey

Homework Statement

http://img41.imageshack.us/i/1721001.jpg/

#17

Homework Equations

D=M/V
F=ma

The Attempt at a Solution

ball
D=5kg/2.5x10^-2
D= 200
density of water is 1000 kg/m^3
1000-200 = 800 kg/m^3
800 = m / 2.5x10^-2
m= 20 kg
F= ma
F = (20)(10) = 200N
but the answer is E)250N

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Apr 24, 2011

dinhjeffrey

nvm answer is 200N, close this thread please

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