Momentum
what is momentum?
force in motion
what is impulse?
a change in momentum
whats the name of a collision where objects rebound with the same speed as they had prior to the collision?
Elastic collision
What does tangential mean?
Something that goes off in one direction parallel to the surface
Write the equation for momentum
p=m x v
write down the equation for impulse
J=Δt・F
equation for elastic collision
m1v1i + m2v2i = m1v1f + m2v2f.
What does centripetal mean?
Pointing towards the center of the circle
If the momentum of something changes that means that=
that object's mass or velocity changed
Now, the bears I live with average, the males, eight to twelve hundred pounds [360 to 540 kg]. They're the largest bears in the world…. They've been clocked at 41 [mph] and they've run a hundred meter dash in 5.85 seconds, which a human on steroids doesn't even approach.
1) v = ∆s/∆tv = 100 m/ 5.85 s; v = 17 m/s
2) p = mv
p = (450 kg)(17 m/s)
p = 7,700 kgm/s
A 0.150-kg baseball moving at a speed of 45.0 m/s crosses the plate and strikes the 0.250-kg catcher's mitt (originally at rest). The catcher's mitt immediately recoils backwards (at the same speed as the ball) before the catcher applies an external force to stop its momentum. If the catcher's hand is in a relaxed state at the time of the collision, then determine the post-collision velocity of the mitt and ball.
0.15 kg • v + 0.25 kg • v = 6.75 kg•m/s
0.40 kg • v = 6.75 kg•m/s
v = 16.9 m/s
Is momentum a scalar or vector quantity?
A vector quantity because momentum is a force in motion towards a certain direction
According to the Guinness Book of World Records, the fastest recorded baseball pitch was delivered by Nolan Ryan in 1974. The pitch was clocked at 100.9 mi/hr (45.0 m/s). Determine the impulse required to give a 0.145-kg baseball such a momentum.
6.52 N•s (or 6.52 kg•m/s)
A 3000-kg truck moving with a velocity of 10 m/s hits a 1000-kg parked car. The impact causes the 1000-kg car to be set in motion at 15 m/s. Assuming that momentum is conserved during the collision, determine the velocity of the truck immediately after the collision.
To determine v (the velocity of the truck), the sum of the individual after-collision momentum of the two objects is set equal to the total momentum.
(3000*v) + 15 000 = 30 000
3000*v = 15 000
v = 5.0 m/s
A car has 30,000 units of momentum. What would be its new momentum if...
1) Its velocity was doubled
2) Its mass was halved
3) Both its velocity and mass was doubled
1) 60,000 units
2) 15,000 units
3) 120,000 units
Kara Less was applying her makeup when she drove into South's busy parking lot last Friday morning. Unaware that Lisa Ford was stopped in her lane 30 feet ahead, Kara rear-ended Lisa's rented Taurus. Kara's 1300-kg car was moving at 11 m/s and stopped in 0.14 seconds.
-1.4 x 10^4 N•s = -14000 Nxs
A 15-kg medicine ball is thrown at a velocity of 20 km/hr to a 60-kg person who is at rest on ice. The person catches the ball and subsequently slides with the ball across the ice. Determine the velocity of the person and the ball after the collision.
o determine v (the velocity of both the objects after the collision), the sum of the individual momentum of the two objects can be set equal to the total system momentum.
(60 • v) + (15 • v) = 300
75 • v = 300
v = 4 km/hr