Dynamics, forces, collisions Flashcards
What’s the unit for time
s
what’s the unit for displacement and distance
m
what’s the unit for acceleration
m s ^ -2
What’s the unit for force
N
What’s the unit for weight
N
What’s the unit for energy
J
What’s the unit for power
W
what’s the unit for momentum
kg m s ^ -1
what’s the symbol for momentum on the formula sheet?
p
what’s the symbol for impulse on the formula sheet
there isn’t a symbol!
Impulse = Fxt
Ft=mv-mu is on the formula sheet
If you have a graph of force against time how do you calculate the impulse?
It’s the area under the curve during the collsion
What is the law of conservation of momentum?
Total momentum before collision is the same as total momentum after collision
How do we write the conservation of momentum as an equation
m1 u1 + m2 u2
m1 v1 + m2 v2
How can we tell if a collision is elastic?
Kinetic energy before collision = kinetic energy after collision
Explain what is meant by an inelastic collision?
Kinetic energy before the collision is greater than kinetic energy after the collision
Explain in terms of the forces acting on it what happens when an object reaches its terminal velocity
The frictional force/drag acting on
the object increases (as its
speed increases).
The frictional force/drag and weight
become balanced.
So it no longer accelerates
