Science Starter What is the formula for momentum? If there is a change in momentum, what does there need to be? What do we call change in momentum? What is the difference between an inelastic and elastic collision? What is Newton’s 3rd Law?

Today’s Agenda Science Starter Kinetic Energy, Momentum, & Impulse Example Problem & Lab Data Analysis Kinetic Energy & Momentum HW

Kinetic Energy, Momentum, & Impulse What is the formula for KE? What are the units for KE? KE is always present when _____ What causes a change in KE? KE=(1/2)mv2 Joules (J) There is movement! An external force (just like change in momentum or impulse)

Example Problem #1 (Inelastic Collision) A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J B A+B

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J B Pi=(4)(0)=0 kg.m/s KEi=(1/2)(4)(0)2=0 J A+B

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J B Pi=(4)(0)=0 kg.m/s KEi=(1/2)(4)(0)2=0 J A+B Pi= 20 + 0= 20 kg.m/s KEi= 100 + 0= 100J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J Pf=(2)(Vf)=20 kg.m/s KEi=(1/2)(2)(Vf)2=100 J B Pi=(4)(0)=0 kg.m/s KEi=(1/2)(4)(0)2=0 J A+B Pi= 20 + 0= 20 kg.m/s KEi= 100 + 0= 100J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J Pf=(2)(Vf)=20 kg.m/s KEi=(1/2)(2)(Vf)2=100 J B Pi=(4)(0)=0 kg.m/s KEi=(1/2)(4)(0)2=0 J Pi=(4)(Vf)=20 kg.m/s KEi=(1/2)(4)(Vf)2=100 J A+B Pi= 20 + 0= 20 kg.m/s KEi= 100 + 0= 100J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J Pf=(2)(Vf)=20 kg.m/s KEi=(1/2)(2)(Vf)2=100 J B Pi=(4)(0)=0 kg.m/s KEi=(1/2)(4)(0)2=0 J Pi=(4)(Vf)=20 kg.m/s KEi=(1/2)(4)(Vf)2=100 J A+B Pi= 20 + 0= 20 kg.m/s KEi= 100 + 0= 100J Pf=Pi  (2+4)Vf=20

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or KEf A Pi=(2)(10)=20 kg.m/s KEi=(1/2)(2)(10)2=100 J Pf=(2)(3.3)=6.7 kg.m/s KEi=(1/2)(2)(3.3)2=11 J B Pi=(4)(0)=0 kg.m/s KEi=(1/2)(4)(0)2=0 J Pi=(4)(3.3)=13.3 kg.m/s KEi=(1/2)(4)(3.3)2=22 J A+B Pi= 20 + 0= 20 kg.m/s KEi= 100 + 0= 100J Pf=Pi  (2+4) 3.3=20 KEi= 11+22 =33 J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or Kef A Pi=20 kg.m/s KEi=100 J Pf=6.7 kg.m/s KEi=11 J B Pi=0 kg.m/s KEi=0J Pi=13.3 kg.m/s KEi=22 J A+B Pi= 20 kg.m/s KEi= 100J Pf=20 KEi=33 J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or Kef A Pi=20 kg.m/s KEi=100 J ΔP= 6.7-20=-13.3 kg.m/s ΔKE= 100-11=89 J Pf=6.7 kg.m/s KEi=11 J B Pi=0 kg.m/s KEi=0J Pi=13.3 kg.m/s KEi=22 J A+B Pi= 20 kg.m/s KEi= 100J Pf=20 KEi=33 J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or Kef A Pi=20 kg.m/s KEi=100 J ΔP= 6.7-20=-13.3 kg.m/s ΔKE= 100-11=89 J Pf=6.7 kg.m/s KEi=11 J B Pi=0 kg.m/s KEi=0J ΔP=13.3-0=13.3 kg.m/s ΔKE= 22-0= 22 J Pi=13.3 kg.m/s KEi=22 J A+B Pi= 20 kg.m/s KEi= 100J Pf=20 KEi=33 J

Example Problem #1 System A B A+B A 2 kg block is moving 10 m/s to the right. The block collides and sticks to a 4kg block at rest. How much energy is generated during this collision? System Pi or KEi Change (Δ) Pf or Kef A Pi=20 kg.m/s KEi=100 J ΔP= 6.7-20=-13.3 kg.m/s ΔKE= 100-11=89 J Pf=6.7 kg.m/s KEi=11 J B Pi=0 kg.m/s KEi=0J ΔP=13.3-0=13.3 kg.m/s ΔKE= 22-0= 22 J Pi=13.3 kg.m/s KEi=22 J A+B Pi= 20 kg.m/s KEi= 100J ΔP=20-20= 0 kg.m/s ΔKE= 33-100= -67J Pf=20 KEi=33 J

Lab Data Analysis Look at the data you have for your scenarios from Tuesday and calculate the change in momentum and kinetic energy for the entire system Confirm that elastic conserves P & KE Confirm that inelastic conserves P, but not KE Complete for at least 2 Elastic & 1 Inelastic

Initial Conditions Outcome Conditions Object 1 Object 2 Mass Vel. Mom Elastic or Inelastic Outcomes Outcome Conditions Object 1 Object 2 Mass Vel. Mom   O O

System Object 1 Object 2 1&2 Pi or KEi Change (Δ) Pf or KEf Initial Conditions Elastic or Inelastic Outcomes Outcome Conditions Object 1 Object 2 Mass Vel. Mom   O O System Pi or KEi Change (Δ) Pf or KEf Object 1 Object 2 1&2

Kinetic Energy & Momentum HW Work on completing tables and answering the questions when your table is complete!