Mechanics (OL) Flashcards
Displacement
The distance from a fixed point in a given direction
Velocity
Rate of change of displacement
Acceleration
Rate of change of velocity
What does SUVAT stand for
S- displacement U- initial velocity V- final velocity A- acceleration T- time
Equation to find velocity
V=u+at
Equation to find displacement
S=ut+1/2at2(squared)
How do you calculate the distance travelled on a distance time graph
The area under the curve
Scalar
Physical quantity with magnitude only e.g. time
Vector
quantity with magnitude and distance e.g. displacement
Momentum (p)
Mass x force
Principal of conservation of momentum
If there are no external forces, total momentum before collision= total momentum after collision
Gravity
Fundamental force of attraction between any two bodies
Friction
A force that opposes relative motion between two bodies in contact
Weight
The force of gravity acting on an object
Newton’s first law of motion
Every object stays at rest or uniform motion in a straight line, unless an external force acts on it
Newton’s second law of motion
The rate of change of momentum is directly proportional to the force , and takes place in the direction of the force
Newton’s third law of motion
For every action there is an equal and opposite reaction
Rate of change of momentum
Final momentum. - initial momentum
——————————-
Time
Impulse
Product of Force x time
Newton’s law of universal gravitation
The force of attraction between any two bodies is directionally proportional to the product of their masses and inversely proportional to the square of the distance between them.
F ~ m1m2
———-
d2
Weightlessness
Falling freely under gravity
Work (J)
Force x displacement
Energy (J)
Ability to do work
Power (W)
Energy
————
Time
Or
Work done
——————
Time
Potential energy (Pe)
mgh
Kenetic energy (Ke)
1/2 mv2(squared)
Moment of a force
Force x perpendicular distance from the fulcrum to the force
T=FxD_|_
Principle of moments
When a body is in equilibrium
Clockwise moments=Anti-clockwise moments
Laws of equilibrium 1
The principle of moments must hold
Principle of moments 2
Forces up=forces down
A couple
A pair of equal but opposite forces
A moment of a couple
Force x distance between them e.g. bike handles, to turn left u must move the right handle anti-clockwise and left handle must move anti-clockwise
