what is force
TRANSCRIPT
What is Force?
1) Force is a push or pull 2) Force is the capacity to do work or cause
physical change 3) Force= Mass times acceleration (F = ma) 4) A force is that which changes or tends to
change the state of rest or motion of a body.
GROUPS OF FORCES: A. Contact Forces : 1. frictional force (friction)- caused by the rubbing of two objects.
2. buoyant force (buoyancy)- it is the upward force of fluids on floating objects.
3. normal force- is the support force on an object which is in contact with another stable object.
4. air resistance force - type of frictional force upon objects as they travel through the air.
5. Tension force - is the pulling force through a string, rope, cable or wire.
6. Spring force - is the force exerted by a compressed or stretched spring upon any
object which is attached to it.7. Applied force - is a force which
is made to an object by a person or another object.
B. Action-at-a-distance forces :
1. gravitation- is the force with which the earth, moon, or other very large object attracts another object towards itself.
2. Electrostatic force – is the force between particles that are caused by their electric charges.
Electric force -
3.magnetic forces – is the force made between magnetic poles
Common Units of Force --->>SI: Newton (N) 1 N = 0.225 lb; One Newton (N) of force is defined as the
amount of force needed to accelerate 1 kilogram (kg) of mass at a rate of 1 meter per second squared (m/s2).
1 Newton = 1 kg m/sec2 (A kilogram is the amount of weight at which 1 N of force will accelerate at a rate of 1 m/s2.)
A force is a vector quantity.
A vector quantity is a quantity which has both magnitude and direction.
Example: 10 Newtons, downwards 25 km, east
A scalar quantity can be described using only 1 quantity, magnitude.
Examples: time, energy, volume, temperature.