Question
An object with a weight of 45 N is thrown into the water. It starts to sink. What can you say about the size of the upthrust force? It is O N It is less than 45 N It is exactly 45 N It is greater than 45 N We don't know anything about the size of the upthrust force
Answer
4
(233 Votes)
Hayley
Professional · Tutor for 6 years
Answer
The upthrust force is less than
.
Explanation
## Step 1The determination of whether an object floats or sinks in a fluid is based on the principle of Archimedes. Archimedes' principle tells us that when an object is put in fluid, there is an upward force – the buoyant force, also known as the upthrust force, which occurs due to the pressure difference at the top and bottom of the object submerged in the fluid. Conversely, gravity exerts a downward force – which is dependent on the weight of the object. ## Step 2For an object to sink in a fluid, its weight of gravity must be more significant than the upthrust force of the fluid. Since our object is sinking, we deduce that the upthrust force should be less than the object weight.