MOTION, ACCELERATION, VELOCITY IN SCIENCE
What is Acceleration?
Acceleration
(velocity), in physics, the rate of change of velocity over time. An
accelerating object is speeding up, slowing down, or changing the direction in
which it is moving. Acceleration is a vector quantity—that is, it
has both a magnitude and a direction. Acceleration describes both the magnitude
of an object’s change in velocity, and the direction in which it is
accelerating. Acceleration can thus involve changes of speed, changes of
direction, or both. As acceleration is a rate of change of velocity over time
and velocity is measured in meters per second (m/s), the units of measurement of
acceleration are meters per second per second (m/s2).
Objects do not speed up, slow down, or change
direction unless they are pushed in some way. Newton’s Second Law (see
Mechanics: The Second Law) sums up this idea, stating that the
acceleration of an object results from the application of a force.
The acceleration (a) of an object with mass (m) produced by a
given force (F) may be calculated using the equation F =
ma. A larger force produces a greater acceleration; a larger mass results in
a smaller acceleration given the same force.
direction unless they are pushed in some way. Newton’s Second Law (see
Mechanics: The Second Law) sums up this idea, stating that the
acceleration of an object results from the application of a force.
The acceleration (a) of an object with mass (m) produced by a
given force (F) may be calculated using the equation F =
ma. A larger force produces a greater acceleration; a larger mass results in
a smaller acceleration given the same force.
What is motion?
Mechanics, branch of physics concerning
the motions of objects and their response to forces. Modern descriptions of such
behavior begin with a careful definition of such quantities as displacement
(distance moved), time, velocity, acceleration, mass, and force. Until about 400
years ago, however, motion was explained from a very different point of view.
For example, following the ideas of Greek philosopher and scientist
Aristotle, scientists reasoned that a cannonball falls down because
its natural position is in the earth; the sun, the moon, and the stars travel in
circles around the earth because it is the nature of heavenly objects to travel
in perfect circles.
the motions of objects and their response to forces. Modern descriptions of such
behavior begin with a careful definition of such quantities as displacement
(distance moved), time, velocity, acceleration, mass, and force. Until about 400
years ago, however, motion was explained from a very different point of view.
For example, following the ideas of Greek philosopher and scientist
Aristotle, scientists reasoned that a cannonball falls down because
its natural position is in the earth; the sun, the moon, and the stars travel in
circles around the earth because it is the nature of heavenly objects to travel
in perfect circles.
The Italian physicist and astronomer
Galileo brought together the ideas of other great thinkers of his
time and began to analyze motion in terms of distance traveled from some
starting position and the time that it took. He showed that the speed of falling
objects increases steadily during the time of their fall. This acceleration is
the same for heavy objects as for light ones, provided air friction (air
resistance) is discounted. The English mathematician and physicist Sir
Isaac Newton improved this analysis by defining force and mass and
relating these to acceleration. For objects traveling at speeds close to the
speed of light, Newton’s laws were superseded by Albert Einstein’s theory of
relativity. For atomic and subatomic particles, Newton’s laws were
superseded by quantum theory. For everyday phenomena, however,
Newton’s three laws of motion remain the cornerstone of dynamics, which is the
study of what causes motion.
Galileo brought together the ideas of other great thinkers of his
time and began to analyze motion in terms of distance traveled from some
starting position and the time that it took. He showed that the speed of falling
objects increases steadily during the time of their fall. This acceleration is
the same for heavy objects as for light ones, provided air friction (air
resistance) is discounted. The English mathematician and physicist Sir
Isaac Newton improved this analysis by defining force and mass and
relating these to acceleration. For objects traveling at speeds close to the
speed of light, Newton’s laws were superseded by Albert Einstein’s theory of
relativity. For atomic and subatomic particles, Newton’s laws were
superseded by quantum theory. For everyday phenomena, however,
Newton’s three laws of motion remain the cornerstone of dynamics, which is the
study of what causes motion.
0 comments:
Post a Comment
Fill free to add your comment or any information bothering you about the site politely. Thanks for your comments in advance.