Finals Review Flashcards
- List two factors that affect the buoyant force acting on an object placed in a fluid.
The volume submerged and the density of the fluid.
- Define Archimedes’ Principle.
An object submerged in a fluid is buoyed up by a force equal to the weight of the fluid displaced.
- What is the factor that determines if an object will sink or float in air?
The density of the object.
- Explain the construction of a thermos bottle. How does each feature reduce or enhance the thermos’ heat transfer capabilities?
Thermos bottles have two layers of walls to prevent heat loss due to conduction, it’s harder for the heat to travel through the air this way. It’s even more effective when there’s a vacuum seal between the two layers. Additionally, the bottle’s inner layer surface is reflective or shiny to prevent radiation of heat. The stopper cup prevents hot air from rising out of the bottle, preventing heat loss due to convection.
Define conduction, convection, radiation and evaporation + examples
- The transfer of heat through the contact of molecules, like a spoon in a pot growing warm due to contact with the heating water.
- The transfer of heat through moving gases and liquids. Heated materials rise, and colder materials are heavier and sink. This is demonstrated by a fire, where warm air rises and then sinks back down to the fire when it gets cold.
- Heat transfer through a vacuum, like someone sitting by a fire and feeling it’s warmth through radiation in the air.
- Heat loss due to water molecules becoming water vapor, the process uses heat to happen and results in heat loss.
- What are the action-reaction pairs when jumping on a trampoline?
Feet on canvas, canvas on feet, canvas on springs, springs on canvas, springs on frame, frame on springs, ground on frame frame on ground.
- What allows you to use a skateboard? Which law applies?
Newton’s first law, because inertia keeps the skateboard going
Who feels the larger force, the car or the fly?
Who feels the impact to a greater extent?
Why and which of Newton’s laws is this?
The force on the bug and the windshield is the same.
The fly.
F = ma, the second law and the third law, every action has an equal opposite reaction. The bug has a smaller mass so it undergoes a larger acceleration compared to the larger mass car who’s acceleration is tiny. The bug is acting on the windshield, the windshield is acting on it.
- Describe two situations where Fnet = 0.
When velocity is 0 and velocity’s constant.
- List all 3 of Newton’s laws and define each.
Newton’s first law: Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by an external force. (Inertia)
Newton’s second law: Fnet = ma (Accel)
Newton’s third law: For every force there is an equal opposite reaction. (Action/Reaction)
Define force, inertia, tension, drag, gravity, friction
Force is push or pull, it’s a vector.
Inertia is a resistance to a change in motion.
Drag is an opposition of motion through air friction.
Friction is a resistance of motion between surfaces.
Tension is force through cables, wires etc.
Gravity is a force between any masses in the universe.
. Explain the difference between a vector and a scalar quantity. List several examples of each.
Scalars have magnitude, like speed, volume, and distance. Vectors have magnitude and direction like velocity, acceleration, displacement, force and momentum.
. Sketch a graph of a velocity versus time graph for an object:
a. Standing still
b. Moving towards you at a constant speed
c. Speeding Up
d. Slowing Down
Sketch a graph of a displacement versus time graph for an object:
a. Standing still
b. Moving at a constant speed
c. Speeding Up d. Slowing Down
- A cyan shirt under green light will appear what color?
Green
