The British gold sovereign coin is an alloy of gold and copper having a total mass of 7.988 g, and is 22-karat gold.

(a) Find the mass of gold in the sovereign in kilograms using the fact that the number of karats = 24× (mass of gold)/ total mass.

(b) Calculate the volumes of gold and copper, respectively, used to manufacture the coin.

(c) Calculate the density of the British sovereign coin.

If you add 10ml of hot water to 10ml of cold water and the change in tempature 8°c calculate how much energy is gained by the cold water

Which best describes how johannes kepler developed his laws of planetary motion

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size