Modern Physics Flashcards
(25 cards)
What is the principle of relativity?
The laws of physics are the same in all inertial frames of reference.
True or False: Time is absolute in the special theory of relativity.
False
What speed is the ultimate speed limit according to special relativity?
The speed of light in a vacuum.
Fill in the blank: According to special relativity, as an object approaches the speed of light, its _____ increases.
mass
What phenomenon occurs due to the relative motion of observers in special relativity?
Time dilation.
What is the formula for time dilation?
Δt’ = Δt / √(1 - v²/c²)
True or False: Length contraction occurs only in the direction of motion.
True
What is the equation that represents length contraction?
L’ = L √(1 - v²/c²)
Define simultaneity in the context of special relativity.
Simultaneity is relative; events that are simultaneous in one frame may not be simultaneous in another.
What is the mass-energy equivalence formula?
E = mc²
Fill in the blank: The Lorentz transformation equations relate the coordinates of two _____ frames of reference.
inertial
True or False: In special relativity, the laws of physics change depending on the observer’s speed.
False
What effect does gravity have on light according to general relativity?
Gravity bends the path of light.
What is the concept of ‘proper time’?
Proper time is the time interval measured by a clock that is at rest relative to the event being measured.
What is the consequence of traveling at speeds close to the speed of light?
Time appears to pass more slowly for the traveler compared to stationary observers.
Fill in the blank: The relativistic addition of velocities formula is used to calculate the resultant velocity when two _____ are moving close to the speed of light.
objects
What is the relativistic velocity addition formula?
u’ = (u + v) / (1 + uv/c²)
What does ‘rest mass’ refer to?
The mass of an object when it is at rest.
True or False: According to special relativity, an object’s mass becomes infinite as it approaches the speed of light.
True
What is the term for the increase of mass with speed in special relativity?
Relativistic mass.
Fill in the blank: The principle of _____ states that the laws of physics are the same for all observers, regardless of their relative motion.
invariance
What is the significance of the Michelson-Morley experiment in relation to special relativity?
It provided evidence against the existence of the ether and supported the idea that the speed of light is constant in all frames.
What is ‘length contraction’?
The phenomenon where an object in motion is measured to be shorter along the direction of motion compared to when it is at rest.
True or False: Mass and energy are interchangeable according to special relativity.
True
