Question

How did Bourne believe that an object could be made to rise or sink at will?

Answer 1

Explanation:

When an object is placed inside water, an upward force is exerted by water called as buoyant force.

An object will float or sink, this completely depends on the density of object. Also, if the magnitude of gravitational force is more as compared to the buoyant force the object will sink otherwise float.

If the density of substance is more than water, it will sink and if the density of substance is less than water it will float.

Answer 2

Bourne believed that an object would float or sink at will as long as he could manipulate the effect's of buoyancy which control and object to sink or float. Hope this helps!