BYU Physics 121 Exam 4 Momentum
and Energy Questions with complete
solution 2025
Momentum (standard) - correct answer ✔p=mv
Momentum (Force) - correct answer ✔F = dp/dt
Impulse (Momentum) - correct answer ✔pf - pi = I
Impulse (Force) - correct answer ✔I = ∫tf-ti (F∆t)
1-D Inelastic Collision - correct answer ✔vf = (m₁v₁+m₂v₂)/(m₁+m²)
1-D Elastic Collision v1f - correct answer ✔v₁f = ((m₁-m₂)/(m₁+m₂))v₁i +
(2m₂/(m₁+m₂))v₂i
1-D Elastic Collision v2f - correct answer ✔v₂f = (2m₁/(m₁+m₂))v¹i + ((m₂-
m¹)/(m₁+m₂))v₂i
Center of Mass (Xcm) - correct answer ✔Xcm = (∑ximi)/(∑mi)
Center of Mass (Rcm) - correct answer ✔Rcm = (1/M)∫Rdm
dm = λdx
Center of Mass(Force) - correct answer ✔∑F=MAcm=M(d²/dt²)Rcm
and Energy Questions with complete
solution 2025
Momentum (standard) - correct answer ✔p=mv
Momentum (Force) - correct answer ✔F = dp/dt
Impulse (Momentum) - correct answer ✔pf - pi = I
Impulse (Force) - correct answer ✔I = ∫tf-ti (F∆t)
1-D Inelastic Collision - correct answer ✔vf = (m₁v₁+m₂v₂)/(m₁+m²)
1-D Elastic Collision v1f - correct answer ✔v₁f = ((m₁-m₂)/(m₁+m₂))v₁i +
(2m₂/(m₁+m₂))v₂i
1-D Elastic Collision v2f - correct answer ✔v₂f = (2m₁/(m₁+m₂))v¹i + ((m₂-
m¹)/(m₁+m₂))v₂i
Center of Mass (Xcm) - correct answer ✔Xcm = (∑ximi)/(∑mi)
Center of Mass (Rcm) - correct answer ✔Rcm = (1/M)∫Rdm
dm = λdx
Center of Mass(Force) - correct answer ✔∑F=MAcm=M(d²/dt²)Rcm
