Mechanics: Moments and Motion Along a Straight Line

what is a moment (of a force about a point)?

force x perpendicular distance from the line of action of the force to the point

what is a couple?

a pair of equal and opposite coplanar forces(forces within the same plane)

how to find the moment of a couple

force x perpendicular distance between the lines of action of forces

the principle of moments

for an object in equilibrium, the sum of all the clockwise moments about any point \= the sum of all the anti-clockwise moments about that point

instantaneous velocity

the velocity of an object at a specific point in time

can be calculated using a tangent-gradient from a displacement-time graph

uniform acceleration

constant acceleration

acceleration-time graphs

area under graph is change in velocity.

velocity-time graphs

gradient=acceleration

area under graph is displacement

displacement-time graphs

gradient \= velocity

suvat

s = displacement

u = initial velocity

v = final velocity

a = acceleration

t = time