All Flashcards
What are the differences between scalar and vector quantities?
Scalar: Magnitude only (e.g., speed, mass, distance). Vector: Magnitude and direction (e.g., velocity, force, displacement).
What happens to an electron beam when a perpendicular uniform magnetic field is applied to it?
Electrons will move in a circular path due to the Lorentz force. This circular motion typically is not accompanied by visible light emission, as this requires specific conditions not mentioned here.
How does a magnetic field affect the kinetic energy of an electron moving through it?
An electron's kinetic energy remains unchanged in a magnetic field because the field does no work on the electron, as it moves perpendicular to the field.
What is the historical significance of measuring the specific charge of electrons?
Measuring the specific charge was crucial for understanding electron properties, playing a key role until the electronic charge was determined by Millikan.
In an arrangement where electric force FE is upwards and magnetic force FB is downwards, under what condition will no net force act on the charged particle?
When F E= FB or when qE = qvB.
What two main components does a Bainbridge mass spectrometer use?
It uses a velocity selector with perpendicular electric and magnetic fields to filter particles by velocity, and a separate magnetic field in a deflection chamber to measure mass.
How does the onko-knife or iknife help surgeons during operations?
It can determine whether tissue is cancerous or not in real time, making the procedure quicker and more accurate.
Is energy conserved for a charge moving in a magnetic field?
Energy is conserved as the magnetic field does no work on a point charge in stable orbit. The charge's speed remains constant while its direction changes.
How does a point charge moving perpendicular to a uniform electric field affect its energy?
As a point charge moves at right angles to a uniform electric field, it experiences a change in kinetic energy, with the energy being derived from the electric field.
What key discovery did Rutherford's experiment with alpha particles and gold atoms lead to?
Rutherford's experiment led to the discovery of the atomic nucleus. When alpha particles were directed at thin gold foil, some were deflected at large angles, indicating a small, dense, positively charged nucleus.
How are electric and magnetic fields utilized in particle accelerators?
In particle physics, electric fields are used to accelerate charged particles to high velocities, while magnetic fields guide and focus beams, or alter particle trajectories during collisions for analysis.
How often does the kinetic energy of a body in simple harmonic motion become zero if it has a frequency of 20 Hz?
In simple harmonic motion, kinetic energy is zero at the points of maximum displacement. Since this occurs twice per cycle, for a frequency of 20 Hz, kinetic energy is zero 40 times per second.
When do energy losses occur in simple harmonic motion?
Energy losses occur when there is resistance, such as air resistance or friction. True simple harmonic motion does not have energy losses.
How do greenhouse gases exhibit simple harmonic motion characteristics?
Greenhouse gas molecules absorb and re-emit electromagnetic radiation, vibrating in a manner akin to simple harmonic oscillators. Their vibrational energy exchange resembles the energy oscillations in SHM.
How is simple harmonic motion related to waves in physics?
Simple harmonic motion (SHM) and wave motion are intimately related. A rotating vector, or phasor, can represent SHM, mirroring a wave particle's motion. The concepts share common terms like amplitude, frequency, and period, illustrating the wave-particle duality in physics.
When does a pendulum have maximum potential energy during its oscillation?
At the oscillation extremes when its speed is zero and it's momentarily stationary, a pendulum's potential energy is at its maximum.
What is the equation for velocity in simple harmonic motion (SHM)?
v = -ωx0 sin(ωt), where v is velocity, ω is angular frequency, x0 is amplitude, and t is time.
What is the equation for acceleration in simple harmonic motion?
a = -ω^2 x. In SHM, acceleration is directly proportional to, and in the opposite direction of, the displacement x and is given by the negative square of the angular frequency (ω) times the displacement.
What does the ± sign signify in the equation for velocity (v = ±ω√(x0^2 − x^2)) in Simple Harmonic Motion?
The ± sign indicates the velocity's direction can vary, showing the object may move in one of two opposite directions at a particular displacement (x) from its equilibrium position.
How is the frequency of oscillation calculated for an object hanging from a vertical spring?
Frequency f = 1/T, with the period T given by T = 2π√(m/k), where m is mass and k is the spring constant.
How do you calculate the speed of an object in simple harmonic motion at a specific displacement?
The speed (v) at a given displacement (x) can be calculated using the formula v = ω√(A² - x²), where ω is the angular frequency and A is the amplitude of the motion.