6+7 forces in equilibrium + on the move Flashcards
what is a scalar quantity
a quantity which has a magnitude but no direction
what is a vector quantity
a quantity which has a magnitude and direction
what is equilibrium
it is when the resultant of two forces is equal to a third force acting in the opposite direction
how do u calculate the moment of a force
moment of a force=
force x perpendicular distance from pivot
what is the principle of moments
for an object in equilibrium, the sum of the clockwise moments will be equal to the sum of the anti-clockwise moments about the same pivot
what happens to the reaction force when an object is equilibrium is supported by 2 pivots
the reaction force will be shared equally between both supports. the size of each reaction will depend on the distance away from the center of gravity
how do you calculate the moment of a couple
moment of a couple=
magnitude of one of the forces x perpendicular distance between forces
what are the two typed of velocity
instantaneous velocity
average velocity
what is instantaneous velocity
the velocity at one particular moment in time
what is average velocity
the total displacement divided by the total time
how do you calculate acceleration
change in velocity/ change in time
what are the three typed of motion graphs
displacement-time graphs
velocity-time graphs
acceleration-time graphs
what does SUVAT stand for
s= displacement
u= initial velocity
v= final velocity
a= acceleration
t= time
what is the SUVAT equation not given in the equation sheet
s= vt - 1/2 at^2
What forces act on an object in free fall
gravity only
what is the acceleration towards the ground of an object in free fall
9.8ms-2
what is a projectile
an object projected at an angle away from the horizontal
what rules do objects travelling with a projectile motion follow
1- the vertical acceleration downwards is always 9.81ms-2 and the horizontal acceleration is always 0
2- the horizontal velocity does not change throughout the motion
3- the value of the time is the same vertically and horizontally
