Buoyancy of Objects (Phase 3) Litres Needed to be Neutral Flashcards
How do you find the litres needed to make an object neutral in water?
The weight in water divided by the weight of water per litre equals the litres needed to be neutral.
An object weighs in seawater 9.7kg.
How much upward force in litres needs to be added to make the object neutral?
9.7kg (weight in water) ÷ 1.03kg (seawater)
= 9.41litres (displaced to be neutral)
An object weighs in fresh water 23kg.
How much upward force in litres needs to be added to make the object neutral?
23kg (weight in water) ÷ 1kg (fresh water)
= 23litres (displaced to be neutral)
An object weighs in seawater 18.05kg.
How much upward force in litres needs to be added to make the object neutral?
18.05kg (weight in water) ÷ 1.03kg (seawater)
= 17.52litres (displaced to be neutral)
An object weighs in fresh water 9kg.
How much upward force in litres needs to be added to make the object neutral?
9kg (weight in water) ÷ 1kg (fresh water)
= 9litres (displaced to be neutral)
An object weighs in seawater 48.9kg.
How much upward force in litres needs to be added to make the object neutral?
48.9kg (weight in water) ÷ 1.03kg (seawater)
= 47.47litres (displaced to be neutral)
An object weighs in fresh water 380kg.
How much upward force in litres needs to be added to make the object neutral?
380kg (weight in water) ÷ 1kg (fresh water)
= 380litres (displaced to be neutral)
An object weighs in seawater 0.94kg.
How much upward force in litres needs to be added to make the object neutral?
0.94kg (weight in water) ÷ 1.03kg (seawater)
= 0.91litres (displaced to be neutral)
An object weighs in fresh water 784.3kg.
How much upward force in litres needs to be added to make the object neutral?
784.3kg (weight in water) ÷ 1kg (fresh water)
= 784.3litres (displaced to be neutral)
An object weighs in seawater 2.5kg.
How much upward force in litres needs to be added to make the object neutral?
2.5kg (weight in water) ÷ 1.03kg (seawater)
= 2.42litres (displaced to be neutral)
If an object in neutral in seawater, what will happen if the same object is moved into fresh water?
If an object is neutral in seawater, it would become negatively buoyant and sink if moved into fresh water.
Seawater weighs more than fresh water, therefore has a greater upward force on an object.
An object is neutral with 15litres of air displaced in a liftbag in seawater.
How many litres need to be added to the liftbag to make it neutral in fresh water?
15litres (neutral in seawater) × 1.03kg (seawater)
= 15.45litres (neutal is fresh water)
Add 0.45litres to liftbag
An object is neutral with 50litres of air displaced in a liftbag in seawater.
How many litres need to be added to the liftbag to make it neutral in fresh water?
50litres (neutral in seawater) × 1.03kg (seawater)
= 50.5litres (neutal is fresh water)
Add 1.5litres to liftbag
An object is neutral with 80litres of air displaced in a liftbag in fresh water.
How many litres need to be subtracted from the liftbag to make it neutral in seawater?
80litres (neutral in fresh water) ÷ 1.03kg (seawater)
= 77.66litres (neutal in seawater)
Subtract 2.34litres to liftbag
An object is neutral with 100litres of air displaced in a liftbag in fresh water.
How many litres need to be subtracted from the liftbag to make it neutral in seawater?
100litres (neutral in fresh water) ÷ 1.03kg (seawater)
= 97.08litres (neutal in seawater)
Subtract 2.92litres to liftbag
An object is neutral with 120litres of air displaced in a liftbag in seawater.
How many litres need to be added to the liftbag to make it neutral in fresh water?
120litres (neutral in seawater) × 1.03kg (seawater)
= 123.6litres (neutal is fresh water)
Add 3.6litres to liftbag
An object is neutral with 150litres of air displaced in a liftbag in fresh water.
How many litres need to be subtracted from the liftbag to make it neutral in seawater?
150litres (neutral in fresh water) ÷ 1.03kg (seawater)
= 145.63litres (neutal in seawater)
Subtract 4.37litres to liftbag
An object is neutral with 5litres of air displaced in a liftbag in seawater.
How many litres need to be added to the liftbag to make it neutral in fresh water?
5litres (neutral in seawater) × 1.03kg (seawater)
= 5.15litres (neutal is fresh water)
Add 0.15litres to liftbag
An object is neutral with 8litres of air displaced in a liftbag in fresh water.
How many litres need to be subtracted from the liftbag to make it neutral in seawater?
8litres (neutral in fresh water) ÷ 1.03kg (seawater)
= 7.76litres (neutal in seawater)
Subtract 0.24litres to liftbag
An object weighs in seawater 9.7kg.
The object needs 9.41lites added to make in neutral.
How would you make the object positively buoyant?
Increase the weight of what the object weighs.
9.7kg (weight in water) + 2kg (extra weight)
= 11.7kg (increased weight)
÷ 1.03kg (seawater)
= 11.35litres (displaced to be positive)
