Momentum
Momentum can be defined as
moving inertia and a vector
Impulse can be defined as...
the change in momentum and force applied to an object for a period of time
What is needed to change the momentum of an object?
You need a large force
Which collision is considered bouncy and another considered sticky?
sticky - inelastic
an object's resistance to a change in motion
direct relationship
= 600 kg (30 m/s) = 18,000 Ns
What would the total momentum be before and after an explosion?
Total momentum is always 0 regarding explosions
total momentum is always 0 in which collision?
explosion collisions
What does inertia depend on the most?
depends on mass
what is the relationship between velocity and momentum?
direct relationship
J= delta p = m delta v = ?
F net t
Why should we always bend our knees when we land?
By increasing the time of impact, you will decrease the force a person feels
Which type of collision has momentum transferred from one object to the other?
Elastic collisions
There is a 250 kg man and a 50 kg girl. Who has more inertia and why?
The man has more inertia because he has more mass
What is the momentum of a 3.0 g bullet moving at 250 m/s?
A hockey player exerts a force of 30 N on a hockey puck for .16 s. What impulse is given to the puck?
J= Fnet t
= 30 N (.16 s) = 4.8 Ns
If a metal bullet penetrates a block while a rubber bullet bounces off, why does the 2nd block tip over and not the first?
Metal bullet does not change direction while a rubber bullet does, so it has a larger change in v, creating a larger force to knock over the block
Which collision do you add masses to determine the velocity after?
Inelastic collisions
There is a man walking at 6 m/s and another man walking at 3 m/s. Who has more inertia?
They have the same inertia, but it would be harder to stop the man who is walking at 6 m/s.
What are the 3 requirements for an object to have momentum?
mass, velocity, and the object must be moving
A force of 100 N acts fir .40 s on a 2 kg ball. What is the impulse given to the ball and the change in momentum?
J = Fnet t = 100 N (.45 s ) = 40 Ns
Impulse= change in momentum
If there are 2 trucks, one crashes into a wall and the other drives through hay, and they both start and end at the same speed, how do their change in p compare?
1st truck stopped in less time creating a larger force while the 2nd truck stopped in more time creating a smaller force. The truck crashing into the wall has a larger and greater impulse
Jenny has a mass of 55 kg and jogging at a pace of 5 m/s. She jogs straight into Al who has a mass of 25 kg. If they both come to a complete stop when they collide, how fast was Al originally running?
m1v1=m2v2
55 kg (5 m/s) = 45 kg v2
v2= 6.1 m/s east
An object is kept in orbit by ______ and ______.
inertia and gravity