DP Physics Questionbank

Description

Nature of science:

Paradigm shift: The fundamental fact that the speed of light is constant for all inertial observers has far-reaching consequences about our understanding of space and time. Ideas about space and time that went unchallenged for more than 2,000 years were shown to be false. The extension of the principle of relativity to accelerated frames of reference leads to the revolutionary idea of general relativity that the mass and energy that spacetime contains determine the geometry of spacetime. (2.3)

Understandings:

• Reference frames
• Galilean relativity and Newton’s postulates concerning time and space
• Maxwell and the constancy of the speed of light
• Forces on a charge or current

Applications and skills:

• Using the Galilean transformation equations
• Determining whether a force on a charge or current is electric or magnetic in a given frame of reference
• Determining the nature of the fields observed by different observers

Guidance:

• Maxwell’s equations do not need to be described
• Qualitative treatment of electric and magnetic fields as measured by observers in relative motion. Examples will include a charge moving in a magnetic field or two charged particles moving with parallel velocities. Students will be asked to analyse these motions from the point of view of observers at rest with respect to the particles and observers at rest with respect to the magnetic field.

Data booklet reference:

Theory of knowledge:

• When scientists claim a new direction in thinking requires a paradigm shift in how we observe the universe, how do we ensure their claims are valid?

Aims:

• Aim 3: this sub-topic is the cornerstone of developments that followed in relativity and modern physics

Directly related questions

• 16N.3.SL.TZ0.4b:

  In the reference frame of the laboratory the force on X is magnetic.

  (i) State the nature of the force acting on X in this reference frame where X is at rest.

  (ii) Explain how this force arises.

• 16N.3.SL.TZ0.4a: Define frame of reference.
• 17M.3.SL.TZ1.3a:

  State what is meant by a reference frame.

• 17M.3.SL.TZ1.3b.i:

  State and explain whether the force experienced by P is magnetic, electric or both, in reference frame S.

• 17M.3.SL.TZ1.3b.ii:

  State and explain whether the force experienced by P is magnetic, electric or both, in the rest frame of P.

• 17M.3.SL.TZ2.3a:

  State one prediction of Maxwell’s theory of electromagnetism that is consistent with special relativity.

• 17M.3.SL.TZ2.3b:

  A current is established in a long straight wire that is at rest in a laboratory.

  

  A proton is at rest relative to the laboratory and the wire.

  Observer X is at rest in the laboratory. Observer Y moves to the right with constant speed relative to the laboratory. Compare and contrast how observer X and observer Y account for any non-gravitational forces on the proton.

   

• 20N.3.SL.TZ0.3c(i): Identify the nature of the attractive force recorded by an observer stationary with respect to...
• 20N.3.SL.TZ0.3a: Maxwell’s equations led to the constancy of the speed of light. Identify what Maxwell’s equations...
• 20N.3.SL.TZ0.3b: State a postulate that is the same for both special relativity and Galilean relativity.
• 20N.3.SL.TZ0.3c(ii): A second observer moves at the drift velocity of the electron current in the wires. Discuss how...
• 20N.3.SL.TZ0.4a: The Lorentz transformations assume that the speed of light is constant. Outline what the Galilean...
• 17N.3.SL.TZ0.4: Outline the conclusion from Maxwell’s work on electromagnetism that led to one of the postulates...
• 18M.3.SL.TZ1.4a.i:

  Calculate, according to Galilean relativity, the time taken for a muon to travel to the ground.

• 18M.3.SL.TZ1.3a:

  State whether the field around the wire according to observer X is electric, magnetic or a combination of both.

• 18M.3.SL.TZ1.3b.ii:

  Deduce whether the overall field around the wire is electric, magnetic or a combination of both according to observer Y.

• 18M.3.SL.TZ1.4a.ii:

  Deduce why only a small fraction of the total number of muons created is expected to be detected at ground level according to Galilean relativity.

• 18M.3.SL.TZ2.3a.i:

  Calculate, for the reference frame of rocket A, the speed of rocket B according to the Galilean transformation.

• 18N.3.SL.TZ0.3b.i:

  explain why the time coordinate of E in frame S is $t=\frac{L}{c}$.

• 18N.3.SL.TZ0.4b.i:

  Determine the time it takes the probe to reach the front of the rocket according to an observer at rest in the rocket.

• 18N.3.SL.TZ0.3b.ii:

  hence show that the space coordinate of E in frame S is $x=L+\frac{vL}{c}$.

• 18N.3.SL.TZ0.3a: State what is meant by a reference frame.
• 19M.3.SL.TZ2.5b: Explain why there is no magnetic force on each proton in its own rest frame.
• 19M.3.SL.TZ2.5c: Explain why there must be a resultant repulsive force on the protons in all reference frames.
• 19M.3.SL.TZ2.4ai: Define an inertial reference frame.
• 19M.3.SL.TZ2.5a: Outline why there is an attractive magnetic force on each proton in the laboratory frame. 
• 19M.3.SL.TZ2.4aii: As the spaceship passes the Earth it emits a flash of light that travels in the same direction as...
• 19M.3.SL.TZ2.4b:

  Use your answer to (a)(ii) to describe the paradigm shift that Einstein’s theory of special relativity produced.

• 19M.3.SL.TZ1.3a: State the speed of the flash of light according to an observer on the ground using Galilean...
• 19M.3.SL.TZ1.3b: State the speed of the flash of light according to an observer on the ground using Maxwell’s...
• 19M.3.SL.TZ1.4a.i:

  Estimate in the Earth frame the fraction of the original muons that will reach the Earth’s surface before decaying according to Newtonian mechanics.

• 19N.3.SL.TZ0.3b(i): State the nature of the force on the particle P in the reference frame of the laboratory.
• 19N.3.SL.TZ0.3b(iii):

  Explain how the force in part (b)(ii) arises.

• 19N.3.SL.TZ0.3b(ii):

  Deduce, using your answer to part (a), the nature of the force that acts on the particle P in the rest frame of P.