Mechanics 1 Flashcards
(20 cards)
Scalar quantities
Have a magnitude only
e.g. Speed
Vector quantities
Have magnitude and direction
e.g. Velocity
Distance
Total distance travelled (m)
Displacement
Distance travelled in a specified direction from a given starting point
Speed
Rate of change of distance
Speed = Distance/Time (ms-1)
Velocity
rate of change of displacement
Velocity = Change in displacement/Change in time (ms-1)
Acceleration
Rate of change of velocity
Acceleration = Change in velocity/Change in time
Mass
The measurement of the amount of matter that an object contains (kg)
Weight
The gravitational force exerted by earth on an object
Weight = Mass x Gravity (N)
Displacement-Time graph
Displacement against time
Gradient = Velocity
Velocity-Time Graph
Velocity against Time
Gradient = Acceleration
Area Under = displacement
Acceleration-Time graph
Acceleration against time
Area under = Change in velocity
Momentum
The amount of oomph an object has
Momentum = Mass x Velocity (kgms-1)
Newton’s 1st Law
“An object will remain in a state of rest, or contiunue to move with a constant velocity unless acted upon by a resultant external force”
Newton’s 2nd Law
“The acceleration of a body of constant mass is proportional to the resultant force applied to it and in the direction of the resultant force.”
Sum of forces = Mass x Acceleration (N)
Newton’s 3rd Law
“While body A exerts a force on body B, body B exerts an equal and opposite force on body A”
Principle of conservation of linear momentum
“In any interaction between bodies, momentum remains constant provided no resultant external force acts.”
Newton’s 2nd Law in terms of momentum
“The resultant force exerted on a body is directly proportional to the rate of change of linear momentum.”
Force = Change in momentum / Change in time (N)
Impulse
The change in momentum of a body caused by a resultant force
Impulse = Force x Change in time (Ns)
Force-Time Graph
Force against time
Area under = Impulse (Change in momentum)
