WorksheetsUnit 4 Review (So Far)
Total questions: 15
Worksheet time: 4hrs 45mins
Which one of the following is a key postulate of special relativity?
The laws of physics are the same in all inertial (uniformly moving) frames of reference.
The speed of light in any medium has the same value, c, in all inertial frames of reference.
A frame of reference that is stationary is an inertial frame.
Relative motion occurs when one object moves with regard to a stationary object.
An unstable particle is moving at a speed of 2.4×108 m s-1 relative to a laboratory. Its lifetime is measured by a stationary observer in the laboratory to be 4.7×10-6 seconds. What is the lifetime of the particle, measured in the rest frame of the particle?
1.69 × 10-6 s
2.82 × 10-6 s
5.87 × 10-6 s
6.00 × 10-6 s
Pions are particles created in the upper atmosphere by cosmic rays from the Sun. Pions decay, with an average rest lifetime of 26 nanoseconds (ns)
in the frame of the high-energy source of each pion
in each pion’s own frame
in any inertial frame
in Earth’s frame
Ultraviolet photons with energy of 6.2 eV are incident on aluminium, which has a work function of 4.3 eV. Determine the maximum kinetic energy of the emitted photoelectrons.
1.9 × 1.6 × 10-19 J
6.2 × 1.6 × 10-19 J
Recall the name of the frequency below which no electrons are emitted from metal surface.
minimum frequency
maximum frequency
threshold frequency
ionisation frequency
The energy levels in an atom are shown in the diagram below. The transition E3 to E1 produces a red emission line in a spectrum. Select one of the following that could produce a blue line.
E4 to E1
E2 to E1
E4 to E3
E4 to E2
The weight of an object on Earth is 550 N. The mass of the object is approximately
56 kg
–56 kg
5400 kg
–5400 kg
The correct definition of Coulomb’s law is
the total electric charge of an isolated system remains constant regardless of changes within the system.
the direction of an induced electric current always opposes the change in the circuit or the magnetic field that produces it.
when the magnetic flux linking a circuit changes, an electromotive force (EMF) is induced in the circuit proportional to the rate of change of the flux linkage.
like electric charges repel and opposite electric charges attract, with a force proportional to the product of the electric charges and inversely proportional to the square of the distance between them.
The graph presents the results of a photoelectric effect experiment. It shows the maximum kinetic energy of photoelectrons (𝐸K) with respect to the frequency of incident photons (𝑓).
The gradient of the linear trend line shown in the graph above represents
Planck’s constant
the work function
the threshold frequency
the power of the light incident on the metal surface
Select the words that correctly complete the description of uniform circular motion.
The motion of an object travelling at a ---------------- -------------in a circle due to a force acting on the object in a -------------- direction to the velocity of the object.
varied speed, parallel
varied acceleration, parallel
constant speed, perpendicular
constant velocity, perpendicular
The diagram shows a wire that is carrying an electric current.
The direction of the magnetic field around the wire at point Y is
up the page.
into the page.
down the page.
out of the page.
Which model of the atom would predict the continuous emission of electromagnetic energy, resulting in the instability of the atom?
Bohr’s model of the atom
Dalton’s model of the atom
Rutherford’s model of the atom
Thomson’s plum pudding model of the atom
A rocket with a velocity of 0.9 c journeys from Earth to a distant planet. An observer on Earth measures the journey to have taken 3.00 years. Calculate the time taken for the journey as measured by a clock on the rocket.
0.95 years
1.31 years
6.88 years
9.48 years
Calculate the resulting radius of circular motion when a 150 g mass travelling at 3.0 m s–1 experiences a centripetal force of 15 N.
3.0 cm
9.0 cm
11 cm
20 cm
Calculate the gravitational field strength at a distance of 3.63 × 108 m from the centre of the Earth
4.96 × 10–27 m s–2
1.80 × 10–18 m s–2
3.02 × 10–3 m s–2
1.10 × 106 m s–2
