Chapter 5 Work and Energy conclusion
... Energy can neither be created not destroyed, but can only be converted from one form to another. Heat energy is the kinetic or vibrational energy of molecules. The result of a non-conservative force is often to remove mechanical energy and transform it into heat. Examples of heat generation: sliding ...
... Energy can neither be created not destroyed, but can only be converted from one form to another. Heat energy is the kinetic or vibrational energy of molecules. The result of a non-conservative force is often to remove mechanical energy and transform it into heat. Examples of heat generation: sliding ...
香港考試局
... light spring fixed at its upper end. When the mass is pulled down 4 cm from its equilibrium position and released from rest, it takes 0.6 s to rise back to its equilibrium position. If the mass is pulled down 5 cm from its equilibrium position and released from rest, how long does it take for the ma ...
... light spring fixed at its upper end. When the mass is pulled down 4 cm from its equilibrium position and released from rest, it takes 0.6 s to rise back to its equilibrium position. If the mass is pulled down 5 cm from its equilibrium position and released from rest, how long does it take for the ma ...
M1.4 Dynamics
... These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable. For more detailed instructions, see the Getting Started presentation. 1 of 48 ...
... These icons indicate that teacher’s notes or useful web addresses are available in the Notes Page. This icon indicates the slide contains activities created in Flash. These activities are not editable. For more detailed instructions, see the Getting Started presentation. 1 of 48 ...
Characteristics of Force
... wecan intuitively sense the meaning of mass, and we can define acceleration if we know the meaning of position and time. We shall not discuss those meanings, but shall concentrate on the new concept of force. The answer is equally simple: "If a body is accelerating, then there is a force on it." Tha ...
... wecan intuitively sense the meaning of mass, and we can define acceleration if we know the meaning of position and time. We shall not discuss those meanings, but shall concentrate on the new concept of force. The answer is equally simple: "If a body is accelerating, then there is a force on it." Tha ...
P1_Rotational Energy and Momentum
... and the Moon is speeding up in its CCW orbital motion. What is happening is that the Earth is exerting a CCW torque on the Moon (giving the Moon more CCW orbital angular momentum) and the Moon is exerting an equal (but opposite) CW torque on the Earth (taking away Earth’s rotational angular momentum ...
... and the Moon is speeding up in its CCW orbital motion. What is happening is that the Earth is exerting a CCW torque on the Moon (giving the Moon more CCW orbital angular momentum) and the Moon is exerting an equal (but opposite) CW torque on the Earth (taking away Earth’s rotational angular momentum ...
Pg 65 The student`s spreadsheet is shown in Fig. 12.5. A B C D 1
... 1. A small spacecraft, known as Beagle 2, is to land on the planet Mars. As the spacecraft enters the planet’s atmosphere, it slows down. When the speed reaches 1600km/h, parachutes open and friction with the atmosphere increases. The spacecraft eventually reaches a steady speed, and then finally it ...
... 1. A small spacecraft, known as Beagle 2, is to land on the planet Mars. As the spacecraft enters the planet’s atmosphere, it slows down. When the speed reaches 1600km/h, parachutes open and friction with the atmosphere increases. The spacecraft eventually reaches a steady speed, and then finally it ...
Forces On Moving Objects
... Previous works7,8 provide successful models of finite-sized elementary particles in a theory of matter. In contrast, some of the deficiencies of physics based on point-like objects are: • Errors of relative distance are used in the calculations based on force laws using the inverse square of the dis ...
... Previous works7,8 provide successful models of finite-sized elementary particles in a theory of matter. In contrast, some of the deficiencies of physics based on point-like objects are: • Errors of relative distance are used in the calculations based on force laws using the inverse square of the dis ...
acceleration and force in circular motion
... usual acceleration of gravity for objects in free fall. Help: [S-7] 2d. Example 2: Rock on a String. Our second example is the case of a rock being whirled around the body at the end of a string as in Fig. 2. The string will only produce a force along its physical direction, as shown in the figure. ...
... usual acceleration of gravity for objects in free fall. Help: [S-7] 2d. Example 2: Rock on a String. Our second example is the case of a rock being whirled around the body at the end of a string as in Fig. 2. The string will only produce a force along its physical direction, as shown in the figure. ...
Study Notes Lesson 14 Momentum
... Change momentum: To change momentum of an object, you need to exert an impulse on it. The impulse must be exerted by something outside the object. Internal foces won’t work since they come in balanced pairs that cancel within the object. If no external push or pull is present, no change in momentum ...
... Change momentum: To change momentum of an object, you need to exert an impulse on it. The impulse must be exerted by something outside the object. Internal foces won’t work since they come in balanced pairs that cancel within the object. If no external push or pull is present, no change in momentum ...
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.