IJC2013 Tut 7 Gravitational Field Tutorial (Q and A)
... It was amazing the number, who just having worked out that g has fallen from 9.81 N kg-1 to 9.45 N kg-1, followed this up by saying that the force on the astronaut was negligibly small when in orbit. The idea that both the astronaut and the satellite are falling freely with the same acceleration was ...
... It was amazing the number, who just having worked out that g has fallen from 9.81 N kg-1 to 9.45 N kg-1, followed this up by saying that the force on the astronaut was negligibly small when in orbit. The idea that both the astronaut and the satellite are falling freely with the same acceleration was ...
Inertia and Momentum
... How do we measure inertia? How does the inertia of a cement mixer compare to a roller skate? ...
... How do we measure inertia? How does the inertia of a cement mixer compare to a roller skate? ...
Lecture15-10
... Power output of the Crab pulsar •Power output of the Crab pulsar, in radio and X-rays, is about 6 x 1031 W (which is about 150,000 times the power output of our sun). Since the pulsar is out of nuclear fuel, where does all this energy come from ? • The angular speed of the pulsar, and so the rotati ...
... Power output of the Crab pulsar •Power output of the Crab pulsar, in radio and X-rays, is about 6 x 1031 W (which is about 150,000 times the power output of our sun). Since the pulsar is out of nuclear fuel, where does all this energy come from ? • The angular speed of the pulsar, and so the rotati ...
backup of mechanics..
... Force is not mass. Just as mass is not weight in the gravitational situation. Force varies with acceleration, mass does not (in the non-relativistic domain we are restricted to). (e) Only with inertial force is F ma. In all other cases F = ma. Force has its own source, its own existence, such as g ...
... Force is not mass. Just as mass is not weight in the gravitational situation. Force varies with acceleration, mass does not (in the non-relativistic domain we are restricted to). (e) Only with inertial force is F ma. In all other cases F = ma. Force has its own source, its own existence, such as g ...
gravitation - Physics Unit
... Suppose we want to project a mass upward with sufficient speed so that it will escape the gravitational clutches of the earth altogether and travel out into the solar system, never refering to earth. This minimum speed that a mass must be have, called the escape velocity. The escape velocity is obta ...
... Suppose we want to project a mass upward with sufficient speed so that it will escape the gravitational clutches of the earth altogether and travel out into the solar system, never refering to earth. This minimum speed that a mass must be have, called the escape velocity. The escape velocity is obta ...
Chapter 5 Work and Energy
... The concept of forces acting on a mass (one object) is intimately related to the concept of ENERGY production or storage. • A mass accelerated to a non-zero speed carries energy (mechanical) • A mass raised up carries energy (gravitational) • The mass of an atom in a molecule carries energy (chemica ...
... The concept of forces acting on a mass (one object) is intimately related to the concept of ENERGY production or storage. • A mass accelerated to a non-zero speed carries energy (mechanical) • A mass raised up carries energy (gravitational) • The mass of an atom in a molecule carries energy (chemica ...
m/s
... change unless its mass, velocity, or both change. Momentum, however, can be transferred from one object to another. The law of conservation of momentum states that if a group of objects exerts forces only on each other, their total momentum doesn’t change. ...
... change unless its mass, velocity, or both change. Momentum, however, can be transferred from one object to another. The law of conservation of momentum states that if a group of objects exerts forces only on each other, their total momentum doesn’t change. ...
Sample Lab 1 - Logos Science
... may need to go through some houses if you walk the resultant.) See Figure 1. Using trigonometry, angle α is: ...
... may need to go through some houses if you walk the resultant.) See Figure 1. Using trigonometry, angle α is: ...
here
... superposition of forces: the effect of any number of forces applied at a point on an object is the same as the effect of a single force equal to the vector sum of the original forces. Any force can be replaced by its components, acting at the same point. ...
... superposition of forces: the effect of any number of forces applied at a point on an object is the same as the effect of a single force equal to the vector sum of the original forces. Any force can be replaced by its components, acting at the same point. ...
Mass versus weight
In everyday usage, the mass of an object is often referred to as its weight though these are in fact different concepts and quantities. In scientific contexts, mass refers loosely to the amount of ""matter"" in an object (though ""matter"" may be difficult to define), whereas weight refers to the force experienced by an object due to gravity. In other words, an object with a mass of 1.0 kilogram will weigh approximately 9.81 newtons (newton is the unit of force, while kilogram is the unit of mass) on the surface of the Earth (its mass multiplied by the gravitational field strength). Its weight will be less on Mars (where gravity is weaker), more on Saturn, and negligible in space when far from any significant source of gravity, but it will always have the same mass.Objects on the surface of the Earth have weight, although sometimes this weight is difficult to measure. An example is a small object floating in a pool of water (or even on a dish of water), which does not appear to have weight since it is buoyed by the water; but it is found to have its usual weight when it is added to water in a container which is entirely supported by and weighed on a scale. Thus, the ""weightless object"" floating in water actually transfers its weight to the bottom of the container (where the pressure increases). Similarly, a balloon has mass but may appear to have no weight or even negative weight, due to buoyancy in air. However the weight of the balloon and the gas inside it has merely been transferred to a large area of the Earth's surface, making the weight difficult to measure. The weight of a flying airplane is similarly distributed to the ground, but does not disappear. If the airplane is in level flight, the same weight-force is distributed to the surface of the Earth as when the plane was on the runway, but spread over a larger area.A better scientific definition of mass is its description as being composed of inertia, which basically is the resistance of an object being accelerated when acted on by an external force. Gravitational ""weight"" is the force created when a mass is acted upon by a gravitational field and the object is not allowed to free-fall, but is supported or retarded by a mechanical force, such as the surface of a planet. Such a force constitutes weight. This force can be added to by any other kind of force.For example, in the photograph, the girl's weight, subtracted from the tension in the chain (respectively the support force of the seat), yields the necessary centripetal force to keep her swinging in an arc. If one stands behind her at the bottom of her arc and abruptly stops her, the impetus (""bump"" or stopping-force) one experiences is due to acting against her inertia, and would be the same even if gravity were suddenly switched off.While the weight of an object varies in proportion to the strength of the gravitational field, its mass is constant (ignoring relativistic effects) as long as no energy or matter is added to the object. Accordingly, for an astronaut on a spacewalk in orbit (a free-fall), no effort is required to hold a communications satellite in front of him; it is ""weightless"". However, since objects in orbit retain their mass and inertia, an astronaut must exert ten times as much force to accelerate a 10‑ton satellite at the same rate as one with a mass of only 1 ton.On Earth, a swing set can demonstrate this relationship between force, mass, and acceleration. If one were to stand behind a large adult sitting stationary on a swing and give him a strong push, the adult would temporarily accelerate to a quite low speed, and then swing only a short distance before beginning to swing in the opposite direction. Applying the same impetus to a small child would produce a much greater speed.