Buoyancy is a force that always acts in a direction, exerted by a fluid on a body placed in the fluid.

Upwards direction

Explanation:

The buoyancy force is caused by the pressure exerted by the fluid in which an object is immersed. The buoyancy force always points upwards because the pressure of a fluid increases with depth.

i think they are all correct

explanation:

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the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.