Metre per second squared

The metre per second squared is the unit of acceleration in the International System of Units (SI). As a derived unit, it is composed from the SI base units of length, the metre, and time, the second. Its symbol is written in several forms as m/s2, m·s−2 or m s−2, or less commonly, as m/s/s.[1]

As acceleration, the unit is interpreted physically as change in velocity or speed per time interval, i.e. metre per second per second and is treated as a vector quantity.

Example

An object experiences a constant acceleration of one metre per second squared (1 m/s2) from a state of rest, when it achieves the speed of 5 m/s after 5 seconds and 10 m/s after 10 seconds. The average acceleration can be calculated by dividing the speed (m/s) by the time (s), so the average acceleration in the first example would be calculated .

Newton's Second Law states that force equals mass multiplied by acceleration. The unit of force is the newton (N), and mass has the SI unit kilogram (kg). One newton equals one kilogram metre per second squared. Therefore, the unit metre per second squared is equivalent to newton per kilogram, N·kg−1, or N/kg.[2]

Thus, the Earth's gravitational field (near ground level) can be quoted as 9.8 metres per second squared, or the equivalent 9.8 N/kg.

Acceleration can be measured in ratios to gravity, such as g-force, and peak ground acceleration in earthquakes.

Conversions

Conversions between common units of acceleration
Base value (Gal, or cm/s2) (ft/s2) (m/s2) (Standard gravity, g0)
1 Gal, or cm/s2 1 0.0328084 0.01 0.00101972
1 ft/s2 30.4800 1 0.304800 0.0310810
1 m/s2 100 3.28084 1 0.101972
1 g0 980.665 32.1740 9.80665 1

See also

References

  1. ↑ Note that the SI standard does not permit the latter: NIST Special Publication 330, 2008 Edition: The International System of Units (SI) p. 130 "A solidus must not be used more than once in a given expression without brackets to remove ambiguities."
  2. ↑ Kirk, Tim: Physics for the IB Diploma; Standard and Higher Level, Page 61, Oxford University Press, 2003
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.