Further Mechanics Flashcards
Linear momentum equation?
ρ = mv
What is the law of conservation of momentum?
Assuming no external forces act, momentum is always conserved.
How ( in what direction ) is energy transferred in collisions?
Parallel to the direction of impact
What is the formula for force relating to momentum?
F =Δρ/Δ t
What is impulse?
Δ Momentum = ΔF x Δt
The change in momentum of an object
What is KE in terms of momentum?
KE = ρ² /2m
What happens to kinetic energy in a collision?
It isn’t always conserved. May be transferred to surroundings
What is an elastic collision?
Collision in which energy is conserved
What’s an inelastic collision?
Total KE after < KE before
In what forms may energy be “lost” ?
Transferred to other stores in the form of heat or sound.
What’s a completely inelastic collision?
One body is embedded in another
If 2 objects have an equal mass in an elastic collision, in what direction will they move away from each other?
90⁰ to each other
What’s angular displacement?
The angle in which you have turned through
θ= s(arc length) / r(radius)
What centripetal force + formula?
The resultant force acting towards the centre of a circle.
F= mv²/r
Or
F=mω²r
What is angular velocity formula?
ω = v / r
Or
ω = 2π / T (period)
In verticle circles, when is the object weight contributing to centripetal force?
At the top
The weight is also acting towards the centre of the circle.
Mg + mv²/r
In verticle circles, when is the object weight contributing against centripetal force?
When the object is at the bottom
The weight is acting away from the circle centre and therefore against the centripetal force.
mv²/r - mg
Formula for centripetal acceleration?
a = v²/r
Or
a = ω²r
