; Momentum
Documents
Resources
Learning Center
Upload
Plans & pricing Sign in
Sign Out
Your Federal Quarterly Tax Payments are due April 15th Get Help Now >>

Momentum

VIEWS: 1 PAGES: 15

  • pg 1
									Momentum
  Tuesday – November 9, 2010
• Title: Collision: Sticky and non-sticky
• Purpose: Develop an understanding of collisions
  and the impact of both mass and velocity on
  momentum
   – Why: Because collisions are vital to understanding everything
     from car crashes to chemical reactions.
   – GLEs: Science Systems, PS1 A-F


• To Do & Question:
   – Pick up a collision worksheet.
   – What is momentum?
                  Collisions
• Define each of the following:
  – Sticky Collisions
     • Occurs when two (or more) objects run into each
       other and stay together as one mass
  – Elastic Collisions
     • Occurs when two (or more) objects run into each
       other and separate after the collision
        Momentum Equations
• Momentum is the product of mass and velocity
  – Equation: r =

• When a collision occurs it can be:
  – Non-sticky
                    Before      After
          m1v1 + m2v2 = m1v1 + m2v2
  – Sticky
                    Before      After
          m1v1 + m2v2 = (m1 + m2)v2
                 Problem
• A basketball with a mass of 2.00kg, at
  rest, is hit by a soccer ball with a mass of
  2.50kg traveling with a velocity of 5.30
  m/s. What is the velocity of the two balls if
  the bounce off each other with equal
  velocities?
              Problem #2
• During an ice skating routine, the male
  figure skater with a mass of 81.8 kg is
  skating with a velocity of 4.3m/s. The
  female skater, with a mass of 50.0 kg has
  a velocity of 1.3 m/s in the opposite
  direction. What is there combined velocity
  after the collision?
                  Conclusion
• Reflection:
  – What is the relationship between mass and
    momentum?
  – What is the relationship between velocity and
    momentum?

• Homework:
  – Complete the momentum worksheet
  – ERP Research Outline is due FRIDAY
  – Complete and submit all missing work
To Crash or Not Crash

The collision of KE, friction, and
normal force (opposite of weight)
                   Friction
• Friction is the force that opposes forward
  motion.
  – It also allows forward motion to occur.


• The coefficient of friction (m) describes
  how much friction exists between two
  objects.
         To crash or not to crash
• A car with a weight of 3200 lb is traveling at a velocity of 34.0 m/s. If
  the brakes have locked-up and the coefficient of friction between the
  tires and road is 0.43, will the car be able to stop before reaching the
  pachyderm 637 meters ahead?

w = mg                            FfK = m FN
w = (1451kg)(-9.8 m/s)            FfK = (0.43)(14219.8 N)
w = -14219.8 N                    FfK = 6114.514 N

FN = -w
FN = - (-14219.8 N)
FN = 14219.8 N
A car with a weight of 3200 lb is traveling at a velocity of 34.0 m/s. If the
 brakes have locked-up and the coefficient of friction between the tires
    and road is 0.43, will the car be able to stop before reaching the
                     pachyderm 637 meters ahead?
w = -14219.8 N                     KE = ½ mv2
FN = 14219.8 N                     KE = ½ (1451 kg)(34.0 m/s)2
FfK = 6114.514 N                   KE = ½ (1677356 kg m2/v2)
                                   KE = 838678 J
W = KE
W = 838678 J

W = Fd
838678 J = (6114.514 N)d
137.161841481 m = d
140m = d
         To crash or not to crash
• A car with a weight of 3200 lb is traveling at a velocity of 34.0 m/s. If
  the brakes have locked-up and the coefficient of friction between the
  tires and road is 0.43, will the car be able to stop before reaching the
  pachyderm 637 meters ahead?
• A truck with a mass of 44000 kg is
  traveling at a velocity of 96.0 km/hr. If
  the brakes have locked-up and the
  coefficient of friction between the tires
  and road is 0.57, will the ursidae 298
  meters ahead survive?
• A truck with a mass of 52000 kg is
  traveling on wet roadway with a
  coefficient of friction with the tires of
  0.12. What is the minimum velocity of
  the truck if there is a blind corner 230m
  before a large red stain on the road?
  There were Alcer alcer antlers found
  near the stain.
                 Solve…
• At what maximum speed can a car safely
  negotiate a horizontal unbanked turn (r =
  51 m) in dry weather (m = 0.95) and in icy
  weather (m = 0.10)?

• Hint:
  FN = mg
  Fc = (mv2)/r
  Ff = mFN

								
To top