The moon’s gravity is 1/6 that of the earth. On earth, the buoyant force on a blueberry in a beer equals the weight of the blueberry, and it bounces up and down in the beer. On the moon, will the blueberry:
a) sink and stay down
b) float and stay at the surface of the beer
c) bounce the same as if on earth
d) float away
Gravity contributes equally to both the weight of an object, mg, and the bouyant force of an object, vg. Since the gravity contributes equally, even though it is 1/6 its value on earth, the blueberry bounces in the beer just the same. Note, this does not work with every beer, it must be a slightly darker beer with just the right density.
a) sink and stay down, incorrect, The buoyant force is still equal to the weight although both are decreased in magnitude.
b) float and stay at the surface of the beer, incorrect, The weight still equals the buoyant force although both are decreased in magnitude.
c) bounce the same as if on earth, correct.
d) float away, incorrect, This would occur if there were no gravity and the blueberry an external force.