Question

# 4. The diagram below shows a solid sphere with mass m = 1.2 kg being held underwater. (The hand holding the ball is not shown.)

(a) On the diagram above (or your own recreation of the diagram) indicate both the magnitude and direction of the force on the sphere due to the liquid pressure at each of the 8 points marked with a dot. (b) Mark onto that same diagram the net buoyancy force on the ball, being sure to keep it approximately to scale with the vectors drawn in part (a) above. (c) When the sphere is released, it remains stationary (i.e. there is no acceleration). Determine the magnitude of the buoyancy force on the sphere. A hollow sphere of the same radius but with less mass is then held underwater. (d) Is the buoyancy force on the hollow sphere less than, the same as, or greater than thebuoyancy force on the solid sphere? Explain your reasoning.[2 marks] (e) If the hollow sphere is released, which of the following best describes the subsequent motion? i. The sphere accelerates upwards ii. The sphere moves upwards at a constant velocity iii. The sphere stays stationary iv. The sphere moves downwards at a constant velocity v. The sphere accelerates downwards vi. We don't have enough information to know.

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