Study the scenario.
A ball with a weight of 0.5 N is submerged under water and then released. There is a net force of 5 N upwards.
How much buoyant force is acting on the ball?
Responses
2.5 N upward
2.5 N upward
5 N downward
5 N downward
5.5 N upward
5.5 N upward
4.5 N upward
4.5 N upward
i got it wrong
The correct answer is 2.5 N upward.
Buoyant force is the force exerted by a fluid on an object submerged in it and is equal to the weight of the fluid displaced by the object.
In this case, the ball has a weight of 0.5 N. When it is submerged under water, it displaces an equal volume of water. The weight of the displaced water (and therefore the buoyant force acting on the ball) is equal to the weight of the water volume displaced, which is equal to the weight of the ball itself (since both have the same volume).
So, the buoyant force acting on the ball is 0.5 N upwards. Since there is also a net force of 5 N upwards, the ball will accelerate upwards with a total force of 5.5 N.