... Eclipsing binaries: measure orbital motion
from variation of apparent brightness.
... Electric Field Simulator
Equations of Stellar Structure Stellar structure and evolution can be
... Consider the net energy per second passing outward through
a shell at radius r. If no energy is created in the shell, then
the amount of energy in equals the amount of energy out, and
dL/dr = 0. However, if additional energy is released or absorbed
within the shell, then dL/dr will be non-zero. Let’ ...
Charged Particles in Magnetic Fields
... Suppose a particle with charge q and mass m moves with velocity vector v. If a force F acts in the same
direction as the velocity v then the particle continues to move in the same direction, but it speeds up. This is
what an electric field can do to charged particles. We can describe it a bit differ ...
Universal Gravitation Principle of Superposition Gravity and the Earth
... all other mass. This is the rst time the concept of gravity was extended beyond the earth to include
planets, moons, and stars. Through careful measurements, he was able to show that the force causing
the curved path of the moon was the same as the force causing objects to fall to the earth. Newton ...
P4 – Explaining Motion
... Big question
A rollercoaster will have a large drop at the start
of the ride. Explain why will no other point on
the roller coaster be as tall as the start of the
Particles and Waves Answers
... 1. Alpha particles have a positive charge. It was therefore concluded that electrostatic
repulsion from a like charge, of very large mass, was required to produce a large angle
deflection. However, as large angle deflections were very rare, and most alpha particles
were undeviated from their origina ...
Higher Homework Assignments – 2013 All these homework
... (b) An alpha particle is accelerated through a potential difference of 100v, in a vacuum.
Calculate its velocity. If the experiment was repeated with an electron, how would the
value of the kinetic energy and velocity of the electron compare with that of the alpha
particle? (no need for a calculatio ...
In theoretical physics, negative mass is a hypothetical concept of matter whose mass is of opposite sign to the mass of normal matter, e.g. −2 kg. Such matter would violate one or more energy conditions and show some strange properties, stemming from the ambiguity as to whether attraction should refer to force or the oppositely oriented acceleration for negative mass. It is used in certain speculative theories, such as on the construction of wormholes. The closest known real representative of such exotic matter is a region of pseudo-negative pressure density produced by the Casimir effect. Although general relativity well describes gravity and the laws of motion for both positive and negative energy particles, hence negative mass, it does not include the other fundamental forces. On the other hand, although the Standard Model well describes elementary particles and the other fundamental forces, it does not include gravity, even though gravity is intimately involved in the origin of mass and inertia. A model that explicitly includes gravity along with the other fundamental forces may be needed for a better understanding of the concept of negative mass.