Untitled Flashcards Set

Physics

The study of the general principles underlying natural phenomena.

Ptolemy’s and Copernicus’ theories

Both were good theories, but Copernicus’ point of view ultimately turned out to be more useful.

Difference between liquids and solids at the microscopic level

Liquids’ atoms move throughout the liquid, while solids’ atoms remain near their original locations.

Block of granite

Is mostly empty space because the atoms making it up are mostly empty space.

Aristotle's view on a book sliding to rest

It stopped because its natural motion is to come to rest.

Galileo's view on a book sliding to rest

It stopped because of friction.

Path of planets if no force acted on them

Straight line with no acceleration.

Acceleration of an auto moving at a steady 50 mph up an incline

Zero acceleration but non-zero velocity.

Car at the top of a hill moving at 50 km/hr

The car is accelerated because its direction of motion is changing.

Speed attained by a falling object after twice the time

Twice as fast.

Main point of Newton’s law of motion

Forces cause acceleration.

Net force on a ball moving upward

Is in the downward direction.

Work done by Max pushing against a wall

None.

Weight of a hunk of gold on the moon vs Earth

1 newton on the moon, because then the gold’s mass would be larger.

Force by the floor on your feet while standing still

There is an upward force by the floor on your feet, even though you are not accelerating.

Action-reaction pair involving a book on a table

The table pushing up on the book and the book pushing down on the table.

Drive force on an auto moving at 50 mph

The forward push by the road on the tires.

Direction of net force on the moon

Directed inward toward Earth.

Similarity between a falling apple and the moon

Both have forces on them toward Earth’s center.

Why astronauts feel weightless in orbit

They are in ‘free fall’ around Earth.

Gravitational force on a 2 kg object compared to a 1 kg object

Twice as large.

Increasing gravitational force between two objects

Moving the two objects closer together.

Nature of Newton’s laws today

Often incorrect when applied to molecular-sized objects.

Condition for a force to do no work on an object

If the object does not move.

Work done lifting a 3 N apple by 2 m

6 J.

Law of conservation of energy violations

Nonsense–no violations of this law have ever been observed.

Rate of doing work

Measured in watts.

Energy conversion when pushing a physics book across a desk

Chemical → thermal.

Energy transformation during photosynthesis

Radiant energy → chemical energy.

Evidence of atomic structure

Brownian motion.

Light waves

Traveling disturbances in an electromagnetic field.

Energy transformations in a coal-fired electric power plant

Chemical → thermal → kinetic → electromagnetic.

Isotopes of the same element

Same chemical properties, but different properties in nuclear processes.

Wave theory of matter support

The double-slit experiment with electrons.

Theory of relativity conclusion

No, lightspeed is not relative.

Effect of excess CO2 in the atmosphere

Heats up the earth by absorbing or trapping infra-red radiation.

Electric field lines

Point in towards negative charges.

Twins Samuel and Samantha scenario

Samuel is older than Samantha when she returns from space.

Gravitational force according to Einstein’s theory

Results from the warping of space-time created by the first object.

Nature of time distinction

The second law of thermodynamics.

Types of radiation produced by the sun

Infra-red, visible, and ultra-violet.

Efficiency of a heat engine

Work output divided by thermal energy input.

Source of all magnetic forces

Charges in motion.

Gravity equivalence according to the principle of equivalence

Acceleration.

Different colors and electromagnetic waves

Correspond to different frequencies.

Forces holding the nucleus together

All of the above.

Observation of laser beam by Sonja

The laser beam moves past her at 300,000 km/s.

Entropy of a system

The amount of microscopic disorganization in the system.

Electric forces and matter

Ordinary matter contains as many electrons as protons, leading to no net macroscopic effect.

Radio signal transmission process

Electrons moving in the antenna send out an electromagnetic wave.

Thermal energy transfer when touching ice

Flows from your hand to the ice.

Ernest Rutherford's atomic experiments

Demonstrated that the atom contains a tiny nucleus.

Automobile efficiency limit

Cannot exceed about 25% due to the second law of thermodynamics.

Current flowing through a wire effect

Gives rise to a magnetic field circulating around the wire.

Observation of Mort on Earth from a spaceship

Mass increased, pulse rate slowed down, and size reduced.

Double slit light experiment outcome

Constructive interference occurs at specific points.

Electron wave packet after accurate velocity measurement

Changes to a new wave packet with low uncertainty in velocity.

Force between two identical plastic rods after rubbing

A repulsive electric force.

Blackbody radiation emission

All objects made of atoms emit some blackbody radiation.

Proton composition

Made of smaller particles known as quarks.

Quanta of the electromagnetic field

Photons.

Isolation of quarks

They cannot be found individually because the force between them is infinitely strong.

Large Hadron Collider

A circular proton-proton accelerator.