Year 2 - Mechanics Flashcards
Formula for moment?
☆ Moment = Force x Perpendicular Distance.
What is the definition of a moment?
☆ The moment of the force measures the turning effect of the force on a rigid body.
Where should moments be taken about usually?
☆ Take moments about unknown variable, to eliminate any unknowns.
What does resting on supports imply?
☆ Equilibrium.
What does tilting about A imply?
assuming a straight line A - B.
☆ Tilting about A -> Rb = 0
What does tilting about B imply?
assuming a straight line A - B.
☆ Tilting about B -> Ra = 0
How can we find Fmax?
☆ Fmax = μR
μ = Coefficient of Friction
R = Normal Reaction Force
What if applied force > Fmax?
Applied forces and Frictional forces are acting on a Box.
☆ The box will accelerate.
What if applied force = Fmax?
Applied forces and Frictional forces are acting on a Box.
☆ Box remains at limiting equilibrium.
What if applied force < Fmax?
Applied forces and Frictional forces are acting on a Box.
☆ Box remains at rest.
If particle is in equilibrium…
☆ F ≤ F max = μR
When a particle is accelerating on a rough plane…
☆ Friction = Fmax = μR
When two objects meet in kinematics, what does this imply?
☆ S = r
In kinematics, what is the formula for an object moving with constant velocity?
v = u + at
r(t) = r(0) + vt
In kinematics, what is the formula for an object moving with constant acceleration?
s = ut+ 1/2 at^2
r(t) = r(0) + ut+ 1/2 at^2
ut+ 1/2 at^2 represents s(t) in kinematics.
If the position of the object is north, what does this imply?
☆ The vector i component = 0
If the position of the object is south, what does this imply?
☆ The vector j component = 0
If the position of the object is north-east, what does this imply?
☆ The vector i component = The vector j component
If the position of the object is north-west, what does this imply?
☆ The vector -i component = The vector j component
In projectile motion, how can we improve the model?
☆ Take into account one of the below:
- Air resistance
- Weight of the ball.
- Spin
In projectile motion, what do we know about the horizontal component of velocity?
☆ Remains constant throughout the journey.
To find the maximum of the distance?
Smax:
☆ Differentiate S, then make it = 0
What does the ‘Speed of Projection’ mean?
☆ Initial Speed = | v |
What does ‘P is moving parallel to j’ imply?
☆ P is moving in the same direction as j.
