Forces and energy est
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(Est)What is force?
A force is an action that can change the motion of an object or deform it by pushing or pulling on it. A force is exerted by one object on another and in one direction:
(est)What is a force expressed in?
Force is expressed in Newtons (N). 1 Newton is equal to the force required to make a 1 kg object accelerate at a rate of 1 m/s 2 .
(est)What is equilibrium?
not moving, constant speed
(est)What is gravitational force?
Gravitational force is a force of attraction acting between all objects. This force depends on the objects’ masses and the distances between them.
(est)How does the mass affect the force of attraction?
The higher the mass, the greater the force of attraction.
(est)Do all planets have the same force of attraction?
no
(est)What is an electromagnetic force?
An electromagnetic force is a force of attraction or repulsion between two objects with an electrical charge or magnetic poles.
(est) what is friction?
Friction is a force that prevents two objects from slipping over each other
(Est) What is adhesion?
Adhesion is the phenomenon by which two surfaces remain in contact with each other without slipping.
(est) What is the strength of adhesion-dependent on?
The nature of the materials in contact. The presence of a lubricant. Temperature The state of the surfaces The strength of the perpendicular force exerted on the surface.
(est) what is effective force?
The force that affects the motion of an object is called the effective force (p.88).
(est)When is work done?
Work is done when a force applied to an object causes it to move in the same direction as the force or one of its components.
(est)Brad is pulling his daughter Ashley on a sleigh. The rope is at an angle of 47 with the horizontal. Brad has a mass of 87kg and exerts a force equal to his weight, and pulls his daughter for a total of 1.0km. how much work is done by brad?
w=581471.8
(est)what is a Joule?
the SI unit of work or energy, equal to the work done by a force of one newton when its point of application moves one meter in the direction of action of the force
(est) What is kinetic energy?
A moving object has the capacity to do work and possesses energy due to its motion. This energy is called kinetic energy.
(est)If the mass of an object is doubled what effect does this have on its kinetic energy?
If the mass of the object is doubled, its kinetic energy is also doubled. If the objects velocity is doubled, then it`s kinetic energy quadruples.
(Est)A baseball pitcher throws a ball weighing about 150 g to another player. What is the kinetic energy of the ball if, at the moment it is caught, its velocity is 5 m/s?
25m/s
(est) What is potential energy?
Gravitational potential energy is the energy reserve of an object based on its mass and height.
(est) What is mechanical energy?
the sum of kinetic energy and potential energy.
(est) What is the relationship between potential energy and kinetic energy?
potential energy transforms into kinetic energy, and kinetic energy converts into potential energy, and then back again.