05 Vectors, Moments And Projectiles Flashcards
What is the effect a force has in a particular direction called?
The component of the force in that direction.
How do you resolve a a component of a force?
By drawing a component triangle
Does a force acting vertically have a horizontal component?
No
Does a force acting horizontally have a vertical component?
No
In vector diagrams where do arrows start?
At the head of the previous one
What is the overall effect of a combination of two or more forces called?
The resultant force
How is the resultant shown in a vector diagram?
A line drawn from the start to finish.
On a question on vector diagrams, when it askes for the direction what does that mean?
Find the angle
Why is a closed triangle of vectors a closed triangle?
Because there is no resultant force and it is in equilibrium.
What is the centre of mass?
The point through which a single force on the body does not cause the body to turn. (The point were all the objects weight appears to act.)
When vectors aren’t perpendicular, how do you find the resultant …etc?
Draw a scale diagram.
What can cause turning effects?
Forces
What is the definition of the moment of a force about a point?
Force multiplied by the perpendicular distance from the point to the line of action of the force.
What is the principle of moments?
For an object to be in equilibrium, the sum of the clockwise moments about a point is equal to the sum of the anticlockwise moments about the same point.
A system is in equilibrium if…
•there is no resultant force acting on it AND
•there is no resultant moments acting on it
What is moments measure in?
Nm