Lab 8 Buoyant Force & Archimedes Principle PHY250L
Student Name:
Access Code (located on the underside of the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and formaṄng when answering text based questions.
Report all equations in a proper mathematical format, with the correct signs and symbols.
Submissions with incomplete or improperly formatted responses may be rejected.
Pre-Lab Questions
1. Archimedes' principle is a fundamental concept in fluid mechanics and relates directly to the
buoyant force. Archimedes' principle states that:
"Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of
the fluid displaced by the object."
In your own words, explain the Buoyant Force as it relates to Archimedes Principle. Ensure that you
discuss this in terms of the equation for Buoyant Force.
The buoyant force is the upward force exerted by a fluid on an object that is either fully or partially
submerged in it. According to Archimedes’ Principle, this force is equal to the weight of the fluid
displaced by the object. In other words, when an object is placed in a fluid, it pushes some of the
fluid out of the way, and the fluid responds by pushing back with an upward force. This force can be
calculated using the equation for buoyant force: Fb=ρVgF_b = \rho V gFb=ρVg, where ρ\rhoρ
represents the density of the fluid, VVV is the volume of fluid displaced, and ggg is the acceleration
due to gravity. If the buoyant force is greater than the object's weight, the object will rise; if it is less,
the object will sink. This principle explains why objects float more easily in denser fluids and why
ships made of heavy materials can still stay afloat by displacing a large volume of water.
,Lab 8 Buoyant Force & Archimedes Principle PHY250L
2. Draw a free body diagram of a hanging mass before it is submerged in water. Make sure to label
your forces and include your handwritten name in the background.
, Lab 8 Buoyant Force & Archimedes Principle PHY250L
3. Draw a free body diagram of a hanging mass after it is submerged in water. Make sure to label your
forces and include your handwritten name in the background. Which force is the force you measure
with the spring scale?
EXPERIMENT 1: EFFECTS OF DENSITY
Introduction Questions
1. Apply Newton’s second law to your free body diagram from Pre-Lab Question 3 to solve for the
magnitude of the buoyant force.
To calculate the magnitude of the buoyant force, I applied Newton’s second law to the free body
diagram of the hanging mass after it was submerged in water. Since the object is at rest and not
accelerating, the net force acting on it is zero. This means the upward forces must balance the
downward force of gravity. The upward forces include the tension in the spring scale and the
buoyant force, while the downward force is the object’s weight. By rearranging the equation
T+Fb=mgT + F_b = mgT+Fb=mg, I solved for the buoyant force as Fb=mg−TF_b = mg - TFb=mg−T.
Therefore, the buoyant force is equal to the object’s weight minus the tension measured by the
spring scale.
2. In this experiment, you will mix objects and liquids of varying densities to demonstrate density’s
connection to buoyancy. Sketch and label the arrangement of objects and liquids in the beaker that
you expect to see. Include your handwritten name in the background.
Student Name:
Access Code (located on the underside of the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and formaṄng when answering text based questions.
Report all equations in a proper mathematical format, with the correct signs and symbols.
Submissions with incomplete or improperly formatted responses may be rejected.
Pre-Lab Questions
1. Archimedes' principle is a fundamental concept in fluid mechanics and relates directly to the
buoyant force. Archimedes' principle states that:
"Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of
the fluid displaced by the object."
In your own words, explain the Buoyant Force as it relates to Archimedes Principle. Ensure that you
discuss this in terms of the equation for Buoyant Force.
The buoyant force is the upward force exerted by a fluid on an object that is either fully or partially
submerged in it. According to Archimedes’ Principle, this force is equal to the weight of the fluid
displaced by the object. In other words, when an object is placed in a fluid, it pushes some of the
fluid out of the way, and the fluid responds by pushing back with an upward force. This force can be
calculated using the equation for buoyant force: Fb=ρVgF_b = \rho V gFb=ρVg, where ρ\rhoρ
represents the density of the fluid, VVV is the volume of fluid displaced, and ggg is the acceleration
due to gravity. If the buoyant force is greater than the object's weight, the object will rise; if it is less,
the object will sink. This principle explains why objects float more easily in denser fluids and why
ships made of heavy materials can still stay afloat by displacing a large volume of water.
,Lab 8 Buoyant Force & Archimedes Principle PHY250L
2. Draw a free body diagram of a hanging mass before it is submerged in water. Make sure to label
your forces and include your handwritten name in the background.
, Lab 8 Buoyant Force & Archimedes Principle PHY250L
3. Draw a free body diagram of a hanging mass after it is submerged in water. Make sure to label your
forces and include your handwritten name in the background. Which force is the force you measure
with the spring scale?
EXPERIMENT 1: EFFECTS OF DENSITY
Introduction Questions
1. Apply Newton’s second law to your free body diagram from Pre-Lab Question 3 to solve for the
magnitude of the buoyant force.
To calculate the magnitude of the buoyant force, I applied Newton’s second law to the free body
diagram of the hanging mass after it was submerged in water. Since the object is at rest and not
accelerating, the net force acting on it is zero. This means the upward forces must balance the
downward force of gravity. The upward forces include the tension in the spring scale and the
buoyant force, while the downward force is the object’s weight. By rearranging the equation
T+Fb=mgT + F_b = mgT+Fb=mg, I solved for the buoyant force as Fb=mg−TF_b = mg - TFb=mg−T.
Therefore, the buoyant force is equal to the object’s weight minus the tension measured by the
spring scale.
2. In this experiment, you will mix objects and liquids of varying densities to demonstrate density’s
connection to buoyancy. Sketch and label the arrangement of objects and liquids in the beaker that
you expect to see. Include your handwritten name in the background.
