Unit 3 Flashcards
impulse is equal to…
…change in momentum
What do you need in order to cause a change in momentum?
Have to exert an impulse.
Impulse equation
impulse = force * time interval = Ft Ft = change in momentum = (change in m*v)
Momentum equation
Momentum = mass * velocity = mv OR mass * speed
Momentum
Inertia in motion
A moving object can have a large momentum if it…
…has a large mass, a high speed, or both.
What produces acceleration?
Force.
Impulse
Change in momentum depends on the force that acts the length of time it acts.
Decrease momentum
Extend the time of contact, reduce the force of the catch.
The impulse required to bring an object to a stop and then to “throw it back again” is…
…greater than the impulse required merely to bring the object to a stop.
Law of Conservation of Momentum
States that, in the absence of an external force, the momentum of a system remains unchanged.
Whenever objects collide in the absence of external forces…
…the net momentum of both objects before the collision equals the net momentum of both objects after the collision.
Elastic collision
When objects collide without being permanently deformed and without generating heat.
Inelastic collision
A collision in which the colliding objects become distorted and generate heat during the collision.
Equation conservation of momentum
net momentum(before collision) = net momentum(after collision)
OR
(net mv)before = (net mv)after
Vector sum of momenta is…
…the same before and after a collision
The force or impulse must be exerted on the object by something….
…outside the object.
Momentum is conserved only when interacting objects move along…
…the same straight path
With the absence of air resistance in space…
gravity is the only opposing force that affects two docking space stations.
Properties of energy
- is conserved
- cannot be created or destroyed
- can change form
- measured in joules