A hollow plastic spherical bobber of mass 0.005 kg and volume of 50 cm3 floats on the surface of a lake supporting a submersed fishhook and a bait with a combined mass of 0.01 kg and a combined volume of 2 cm3. The density of water is 0.001 kg/cm3.
If a fish grabs the bait, find the minimum downward force, Ffish, it must exert to pull the bobber completely under the surface of the water. You may assume that the apparent weight of the fish is zero, and the fishing line is completely slack.
So you want the bouyant force of the submerged bob.
Mass: .005+.01 kg
Volume: 50cm^2+2cm^2
mass of displaced water: densitywater*volume=1g/cm^3*52cm^2=52g
bouyant force= 9.8N/Kg * (.052kg)
net force=9.8(52-15)N
check my thinking.
thank you so so so much. the answer is .3626
The force that is
The force that is exerted by the bobber and the hook and bait will be equal to the combined mass and the combined volume (0.015 kg and 52 cm^3)-- not sure why though.
The buoyant force if the object was completely submerged would be the density of water*V displaced*g (.001*52*9.8).
The difference between these two (0.3626) would be the force the fish would need to exert to completely submerge the bobber.
To find the minimum downward force the fish must exert to pull the bobber completely under the surface of the water, we need to consider the buoyant force acting on the bobber.
The buoyant force is the upward force exerted by a fluid on a submerged or floating object. It is equal to the weight of the fluid displaced by the object.
First, let's calculate the weight of the fluid displaced by the bobber and the bait.
The volume of the bobber is 50 cm^3 and the volume of the bait is 2 cm^3. Hence, the total volume of the bobber and the bait is 50 cm^3 + 2 cm^3 = 52 cm^3.
Since the density of water is 0.001 kg/cm^3, the mass of the fluid displaced is 52 cm^3 * 0.001 kg/cm^3 = 0.052 kg.
Now, let's calculate the buoyant force acting on the bobber and the bait.
The buoyant force can be calculated using the equation:
Buoyant force = Weight of the fluid displaced = mass of the fluid displaced * acceleration due to gravity
The acceleration due to gravity is approximately 9.8 m/s^2.
So, the buoyant force on the bobber and the bait is 0.052 kg * 9.8 m/s^2 = 0.5096 N.
Since the bobber is floating on the surface of the water, the buoyant force is equal to the weight of the bobber and the bait.
Therefore, the minimum downward force the fish must exert to pull the bobber completely underwater is equal to the buoyant force, which is 0.5096 N.