P8 Forces in balance Flashcards
Scalar quantities have…
Magnitude but no direction
Vector quantities have…
Magnitude and direction
Examples of scalar quantities (6)
Distance, speed, time, mass, energy and power
Examples of vector quantities (5)
Displacement, velocity, force, weight and momentum
What is displacement?
Distance travelled in given direction
What is the unit of force?
Newtons (N)
Examples of contact forces (2)
Friction and air resistance
What is Newtons third law of motion?
When two objects interact with each other, they exert equal and opposite forces
What is the resultant force?
A single force that has the same effect as all the forces acting on an object
What happens to an object if the resultant force is zero?
The object stays at rest or stays at the same speed and direction
What happens to an object if the resultant force is greater than zero?
The speed or direction of the object will change
What does a free body force diagram show?
All of the forces acting on a single object
What is moment?
The turning effect of a force
What is the equation for moment?
Moment (Nm) = Force (N) x perpendicular distance to pivot (m)
How can you increase the size of the moment?
Increasing the magnitude of the force, increasing the perpendicular distance to the pivot