Chapter 4 - Forces in Action Flashcards
Newton’s First Law
An object will remain in the same state of motion for as long as the forces acting on it are balanced.
Newton’s Second Law
The rate of change of momentum of an object is directly proportional to the resultant force acting on it (F=ma).
Newton’s Third Law
The force acting from body A on body B will be equal and opposite to the force acted on body A from body B.
1 Newton
The force required to accelerate a 1kg mass by 1ms^-2
Centre of Mass
The point of an object at which we can imagine it’s entire mass is concentrated.
Centre of Gravity
The point of an object at which we can imagine its entire weight is acting.
Upthrust
An upward buoyancy force acting on an object in a fluid.
Normal Contact Force
A force arising when one object rests against another.
Tension
The force within a stretched cable or rope.
Friction
The force that arises when two objects rub against each other.
Drag
A force that opposes the motion of an object in a fluid.
Factors Affecting Drag
Speed, cross sectional area, and shape (maybe).
Terminal Velocity
The constant speed that a free falling object eventually reaches when the resistance of the medium it’s falling through = its weight.
Moment
The turning effect of a force about some axis or point.
Couple
When 2 forces are equal in size and opposite in direction, but not along the same line.
