Mechanics Flashcards
What is the difference between a scalar and a vector ?
Scalar has only magnitude, Vector has magnitude and direction
How do you find the forces at a right angle ?
Pythagoras’ theorem
If a force is 50 degrees to the horizontal, how do you find the horizontal and vertical components ?
Horizontal : Fsin(50)
Vertical : Fcos(50)
What is Neutons 1st Law ?
When the resultant force is 0;
Objects at rest stay at rest
Objects in motion stay in that same motion
What is Newton’s 2nd law ?
Force = Mass x Acceleration
F = ma
What is Neuton’s 3rd law ?
When body A puts a force on body B
Body B puts a force equal in magnitude, but opposite in direction on body A
How to find the overall force of any given forces ?
Make an enclosed triangle
What is the gradient of a S-T graph ?
Velocity
What is the area and gradient of a V - T graph ?
Area : Displacement
Gradient : Acceleration
What is the area of an A - T graph ?
Velocity
When can suvat equations be used ?
Constant acceleration
3 or more values
Follows a straight path
What is the equation for momentum ?
momentum = mass x velocity
P = m x v
What is conservation of momentum ?
In the absence of external forces;
momentum before = momentum after
What is the definition of a moment ?
Force x Perpendicular distance between line of action of force to pivot
What is the definition of a torque (τ)
Fs
Force x distance
