Question #9b43a

1 Answer
Jan 19, 2018

0.185 kg

Explanation:

Archimedes Principle tells us that for a floating body of mass #sf(m)#, the upthrust = the weight of water displaced:

#sf(U=mg)#

Water has a density #rho# of #sf(1000color(white)(x)"kg""/""m"^3)#

This means that:

#sf(U=(rhoxxv)gcolor(white)(x)N)#

#:.##sf(U=1000xx0.00250=0.250gcolor(white)(x)N)#

This will be equal to the total weight of the cup + coins.

#:.##sf(mcancel(g)=0.250cancel(g)color(white)(x)N)#

This means that the total mass of the cup + coins #=sf(0.250color(white)(x)kg)#

The mass of coins alone will therefore be

#sf(0.250-0.0650=0.185color(white)(x)kg)#