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# Why does upthrust increase as you lower an object in water? watch

1. Why does upthrust increase as you lower an object in water?
2. The further down you submerge an object in water, the more pressure is exerted on it because of the weight of water above said object. The pressure at the bottom of the water is greater than the pressure at the surface. This pressure difference produces an upwards thrust.

The upwards thrust is basically buoyancy. If an object's density is lower than that of the liquid then it will float; vice versa if the objects density is greater than the liquid because the weight of said object is greater than the weight of the volume of water which is being displaced by said object.
3. The upthrust only increases as more of the object is submerged.

Once it's fully submerged, the upthrust won't change again (unless the density of the water changes with depth)

The upthrust is due to the fact that pressure increases with depth, so the pressure (hence the force) at the bottom of the object pushing UP is greater than the pressure (hence the force) at the top of the object pushing DOWN. The difference in the pressure depends on the distance between the top and bottom of the object and not on its depth below the surface.

Hope this helps to clarify.
4. (Original post by phys981)
The upthrust only increases as more of the object is submerged.

Once it's fully submerged, the upthrust won't change again (unless the density of the water changes with depth)

The upthrust is due to the fact that pressure increases with depth, so the pressure (hence the force) at the bottom of the object pushing UP is greater than the pressure (hence the force) at the top of the object pushing DOWN. The difference in the pressure depends on the distance between the top and bottom of the object and not on its depth below the surface.

Hope this helps to clarify.
Thank you so much! This makes much more sense.

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