A block of wood weighing 25 N is submerged under water. If the net force on the wood is 5 N upward, how much buoyant force is acting on the wood?

A. 30 N upward
B. 25 N downward
C. 20 N upward
D. 5 N upward

just finished the test, the answer is

A. 30 N upward
hope this helps!! <3

The buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. In this case, the weight of the wood is 25 N, and the net force on the wood is 5 N upward.

Since the buoyant force always acts in the opposite direction to the net force, the magnitude of the buoyant force is equal to the difference between the weight of the wood and the net force. Therefore, the buoyant force is given by:

Buoyant force = Weight of object - Net force

Buoyant force = 25 N - 5 N

Buoyant force = 20 N

So, the buoyant force acting on the wood is 20 N upward.

The answer is C. 20 N upward.

To find the buoyant force acting on the wood, we need to understand the concept of buoyancy. According to Archimedes' principle, the buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid displaced by the object.

In this case, the wood is submerged underwater, so it displaces some water. The weight of the water displaced is equal to the buoyant force.

Now, we know the net force acting on the wood is 5 N upward. The weight of the wood is 25 N, which means there must be a downward force acting on it (gravity) to balance the upward force and create the net force. Since the buoyant force acts upward, it must be equal to the difference between the weight of the wood and the net force acting on it.

Therefore, the buoyant force is calculated as:

Buoyant force = Weight of the wood - Net force
Buoyant force = 25 N - 5 N
Buoyant force = 20 N upward

So, the correct answer is C. 20 N upward.