TOPIC FOUR - Mechanics Flashcards
what does the area of a velocity-time graph show?
distance travelled
what does the gradient of a velocity-time graph show?
acceleration
what does the area of an acceleration-time graph show?
change in velocity
what does the gradient of a displacement-time graph show?
velocity
what does the area of a force-time graph show?
change in momentum
what does the area of a force-distance graph show?
workdone
what is newtons 1st law?
an object will remain at rest or constant velocity unless acted on by an external force
what is newtons second law?
the rate of change of momentum is directly proportional to the resultant external force
what is newtons 3rd law?
when body A exerts a force on body B, body B exerts an equal but opposite force on body A
what is the definition of a moment?
force x perpendicular distance from the point of the line of action of the force
what is the principle of moments?
the sum of anticlockwise moments = the sum of the clockwise moments
what is a couple?
a pair of equal forces acting in opposite directions
what is torque? and equation?
torque = the moment of a couple torque = force x perpendicular distance from the point of the line of action of the force
what is thinking distance? what is its equation?
- distance travelled in the time taken to react
- s1 = speed x reaction time
s1 = ut
what is braking distance? what is its equation?
- distance travelled in time taken to stop safely from when brakes are first applied
- s2 = u^2/2a
