Physics help needed

It’s one of the shortcomings of having tests that supply the answers but not the methodology. We need your help. We know the question. We know the answer. We can’t connect them. Can you help us?

A rectangular barge 5.0m long and 2.0m wide, floats in fresh water. How much deeper will it float when its load is a 500kg horse?

Answer: 5cm


5 thoughts on “Physics help needed

  1. momco3 says:

    1 gram of water takes up 1 cubic cm.
    500 kg horse = 500,000 g horse, so it should displace 500,000 cu cm water. The barge’s area is 500 cm x 200 cm = 100,000 square cm. 5 cm (depth) x 100,000 (area) = volume water displaced.

  2. moominmamma says:

    Yes, basically you’re displacing 500 additional kg (i.e. 500 additional litres) of water. You just have to spread that 500 litres over the L&W dimensions of the barge. 500 litres is 500,000 cm^3, so divide that volume by the L & W of the barge to get the depth to which it sinks in order to displace the additional amount.

    The explanations above are correct, but sometimes multiple slightly different explanations help.

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