Collisions. Review Momentum is a quantity of motion. p = mv A change in momentum is called impulse. Impulse =  p = m  v Impulses are caused by forces.

Slides:

Advertisements

Similar presentations

Aim: How can we apply conservation of momentum to collisions? Aim: How can we apply conservation of momentum to collisions? Identify conservation laws.

Advertisements

CHAPTER 7 Impulse and Momentum. Objective Define and calculate momentum. Describe changes in momentum in terms of force and time. Source: Wikimedia Commons.

Conservation of Momentum The sum of the momentums of two bodies before they collide is equal to the sum of their momentums after they collide if there.

Linear Momentum Vectors again.

A pitcher claims he can throw a 0

Center of Mass and Linear Momentum

Momentum and Energy in Collisions. A 2kg car moving at 10m/s strikes a 2kg car at rest. They stick together and move to the right at ___________m/s.

Aim: What is the law of conservation of momentum? Do Now: A 20 kg object traveling at 20 m/s stops in 6 s. What is the change in momentum? Δp = mΔv Δp.

Momentum Impulse, Linear Momentum, Collisions Linear Momentum Product of mass and linear velocity Symbol is p; units are kgm/s p = mv Vector whose direction.

A sticky 6kg lump of clay moves toward the East at 2 m/s. A second ball of clay of 2kg moves to the West at 10 m/s. When the two collide and stick together,

Principles of Physics. - property of an object related to its mass and velocity. - “mass in motion” or “inertia in motion” p = momentum (vector) p = mvm.

Momentum Chapter 8. Momentum Chapter 8 Objectives Define momentum. Define impulse and describe how it affects changes in momentum. Explain why an impulse.

Conservation of Momentum. Conserved Total momentum of a system before and after an interaction remains constant Momentum before = Momentum After Two balls.

Conservation of Momentum Physics 11. Quick Questions to Discuss with neighbour  If you throw a ball against a wall, which of the three impulses is the.

Momentum Chapter 6. Momentum ► Related to inertia, not the same. ► Symbol is p ► p=mv ► Units of kgm/s ► What is the momentum of a 75kg rock rolling at.

Momentum and Impulse Review 1.The velocity of a moving mass is called? ans: momentum 2.Force applied in a period of time is called? ans: impulse 3. The.

CHAPTER 7 MOMENTUM AND COLLISIONS

Impulse and Momentum Questions

1 PPMF102– Lecture 3 Linear Momentum. 2 Linear momentum (p) Linear momentum = mass x velocity Linear momentum = mass x velocity p = mv p = mv SI unit:

Chapter 7 Impulse and Momentum. There are many situations when the force on an object is not constant.

Momentum and Impulse. Answer Me!!! Forces cause objects to start moving. What keeps an object moving after the force is no longer applied?

Momentum A measure of how difficult it is to change an object’s motion (to make it stop or swerve). On what does this difficulty depend? –More mass; more.

Chapter 7 Impulse and Momentum.

Chapter 5: Momentum Momentum: a measure of motion

Chapter 7 Impulse and Momentum. 7.1 The Impulse-Momentum Theorem DEFINITION OF IMPULSE The impulse of a force is the product of the average force and.

Momentum Introduction to Momentum. What is Momentum? The quantity of motion of a moving body Depends on mass and velocity Measured by multiplying mass.

Ch 7. Impulse and Momentum

MOMENTUM AND COLLISIONS. Momentum is the product of the mass and velocity of a body. Momentum is a vector quantity that has the same direction as the.

Momentum is what Newton called the “quantity of motion” of an object. Momentum.

The Law of Conservation of Momentum

Concept Summary. Momentum  Momentum is what Newton called the “quantity of motion” of an object.

Momentum Momentum and Collisions Momentum Banging things around…

Momentum Physics Physics Definition : Linear momentum of an object of mass (m) moving with a velocity (v) is defined as the product of the mass.

Linear Momentum Problems MC Questions Linear Momentum 07 LH.

The force on an object may not be constant, but may vary over time. The force can be averaged over the time of application to find the impulse.

2.6 Understanding Impulse and Impulsive Force

Unit 2 Momentum and Impulse An Introduction to Momentum.

Momentum A measure of how difficult it is to change an object’s motion (to make it stop or swerve). On what does this difficulty depend? –More mass; more.

Chapter 7 Impulse and Momentum. 7.1 The Impulse-Momentum Theorem There are many situations when the force on an object is not constant.

Chapter 7 Impulse and Momentum. You are stranded in the middle of an ice covered pond. The ice is frictionless. How will you get off?

Momentum and Impulse Momentum Momentum can be defined as "mass in motion." All objects have mass; so if an object is moving, then it has momentum Momentum.

Chapter 9 Momentum Is equal to the mass of an object times the velocity of an object Has the symbol “p” so p= m v - measured in kgm/s - It is a vector.

Chapter 7 Impulse and Momentum

1 Honors Physics Chapter 9 Momentum and Its Conservation.

Chap 8.3 and 8.4 Conservation of Momentum

Momentum & Impulse. What does it mean to say “roll with the punches?” Why is it important to wear a helmet? Is it a good thing that cars basically crumble.

Ch 6 Momentum and Collisions. Lab Day Objective In this chapter we will learn: – How to calculate momentum and impulse – Conservation of Momentum – Collisions.

Chapter 7 Impulse and Momentum. 7.1 The Impulse-Momentum Theorem There are many situations when the force on an object is not constant.

Bell Ringer After reading the article Does slamming on the brakes save your brake pads? Do you believe this saves gas?

Chapter 6 Momentum and Impulse

Momentum and collisions. What is momentum?  Momentum is the mass and velocity of a moving object. We find it mathematically using the formula: p = mv.

Momentum The property of moving object has that makes it difficult to stop. (technically, product of mass and velocity) Formula: p = mv.

Do Now: A 1500 kg car speeds up from 15 m/s to 30 m/s in 6 seconds.

Chapter 7 Impulse and Momentum.

Conservation of Momentum

Conservation of Momentum

p = mv v p m B. Momentum Momentum quantity of motion

AP Physics Chapter 6 Momentum and Collisions

Chapter 7 Impulse and Momentum.

Conservation of Momentum

Now consider two tennis balls……

AP Physics Chapter 6 Momentum and Collisions

Chapter 7 Impulse and Momentum.

Chapter 7 Impulse and Momentum.

Momentum Mass X Velocity.

p = mv v p m B. Momentum Momentum quantity of motion

Lesson 10: Conservation of Momentum

Presentation transcript:

Collisions

Review Momentum is a quantity of motion. p = mv A change in momentum is called impulse. Impulse =  p = m  v Impulses are caused by forces applied over time.  p = Ft

Collisions Collision – an isolated event in which 2 or more bodies exert strong forces over short periods of time against each other. Momentum is conserved in all collisions (assuming no outside force). “sticky” collision – objects stick together after colliding and move as one. “non-sticky” collision – objects bounce apart after colliding.

Collisions A train car with a mass of 3.00x10 4 kg traveling north at 1.5 m/s collides and couples with a 3.20x10 4 -kg train car going south at 0.80 m/s. What is the velocity of the coupled cars after the collision?

Collisions Sketching the situation can help. North 1.5 m/s m/s mass = 3.20x10 4 kgmass = 3.00x10 4 kg p 1 = m 1 v 1 p 2 = m 2 v 2 p 1 = (3.00x10 4 kg)(1.5 m/s)p 2 = (3.20x10 4 kg)(-0.80 m/s) p 1 = 4.5x10 4 kg*m/sp 2 = -2.6x10 4 kg*m/s p total = (4.5x10 4 kg*m/s) + (-2.6x10 4 kg*m/s) = 1.9x10 4 kg*m/s

Collisions North m total = 6.20x10 4 kg p total = 1.9x10 4 kg*m/s p = mv v = p/m v = (1.9x10 4 kg*m/s) / (6.20x10 4 kg) = 0.31 m/s north

Collisions A 20.0-kg ball is moving north at 4.00 m/s toward a 5.00-kg ball that is stationary. After they collide, the 20.0-kg ball is moving at 2.40 m/s north. What is the 5.00-kg ball’s velocity after the collision? Neglect friction.

Collisions Before Collision m 2 = 5.00 kg North m 1 = 20.0 kg 4.00 m/s p 1 = m 1 v 1 p 2 = m 2 v 2 p 1 = (20.0 kg)(4.00 m/s)p 2 = (5.00 kg)(0 m/s) p 1 = 80.0 kg*m/sp 2 = 0 kg*m/s p total = (80.0 kg*m/s) + (0 kg*m/s) = 80.0 kg*m/s

Collisions After Collision m 2 = 5.00 kg North m 1 = 20.0 kg 2.40 m/s ??? p total = 80.0 kg*m/s p 1 = (20.0 kg)(2.40 m/s) p 1 = 48.0 kg*m/s p 2 = (80.0 kg*m/s) – (48.0 kg*m/s) = 32.0 kg*m/s v 2 = p 2 / m 2 v 2 = (32.0 kg*m/s) / (5.00 kg) = 6.40 m/s

Collisions A kg bullet strikes a stationary wooden block with a mass of 40.0 kg on a frictionless surface. After the impact, the block-bullet combo is moving at 0.20 m/s. What was the bullet’s original velocity?

Collisions Before Collision 40.0 kg m 1 = kg p 1 = m 1 v 1 Don’t know! p 2 = m 2 v 2 p 2 = (40.0 kg)(0 m/s) p 2 = 0 kg*m/s ??? p total = Don’t know yet!

Collisions After Collision m total = kg = 40.0 kg 0.20 m/s p total = m total v = (40.0 kg)(0.20 m/s) = 8.0 kg*m/s

Collisions Before Collision 40.0 kg m 1 = kg p total = 8.0 kg*m/s ??? v 1 = p 1 / m 1 v 1 = (8.0 kg*m/s) / ( kg) v 1 = 940 m/s

Recoil (Collision in Reverse) Whenever one object pushes another object away, momentum is still conserved. Think of it like a collision in reverse.

Recoil A 60.-kg student on ice skates stands at rest on a frictionless frozen pond holding a 10.-kg brick. He throws the brick east with a speed of 18 m/s. What is the resulting velocity of the student?

Recoil Before Throwing m 1 = 60. kgm 2 = 10. kg p total = 0 kg*m/s

Recoil p total = 0 kg*m/s After Throwing m 1 = 60. kgm 2 = 10. kg 18 m/s??? p 2 = m 2 v 2 p 2 = (10. kg)(18 m/s) p 2 = 180 kg*m/s p 1 + p 2 = p total p 1 + (180 kg*m/s) = 0 kg*m/s p 1 = -180 kg*m/s v 1 = p 1 / m 1 = (-180 kg*m/s) / (60. kg) v 1 = -3.0 m/s