AP Workbook 5-J-1
AP Workbook 5-J-1
AP Workbook 5-J-1
NAME DATE
Scenario
Angela and Carlos have identical masses M and stand on
identical light carts with bearings with negligible friction.
Carlos holds a heavy ball of mass m. At time t = 0, Carlos throws
the ball so that it has a horizontal component of velocity v while
a projectile. At time t = T, Angela catches the ball at the same
height from which it was thrown.
Argumentation
PART A: Which student moves with faster speed for time t > T ? Explain your reasoning qualitatively without
manipulating equations.
Quantitative Analysis
PART B: Derive expressions for v fA and v fC , Angela and Carlos’s final speeds for time t > T in terms of M , m ,
and v.
Initially, Carlos and the ball are at rest, so their initial momentum is
zero, so their final momentum must also be zero.
For the second part of the problem, the system is the ball and
Angela. There are no net horizontal external forces, so the
momentum of the system is conserved.
Initially, Angela is at rest and the ball has momentum mv, which
means that the final momentum must also equal mv. After the
collision, the ball and Angela have a new velocity vfA.
| 149
Return to Table of Contents
© 2019 College Board
5.J Explosions
Data Analysis
PART C: Explain how your expressions in Part B support your reasoning in Part A.
PART D: Let E1 be the mechanical energy of the Angela-Carlos-ball system for t < 0, let E2 be the mechanical
energy of this system for 0 < t < T, and let E3 be the mechanical energy of this system for t > T. Rank
these energies from highest to lowest and explain your reasoning.
Highest energy Lowest energy
Checklist
I answered the question directly.
I stated a law of physics that is
always true.
I connected the law or laws
of physics to the specific
circumstances of the situation.
I used physics vocabulary (energy,
mass, momentum, conservation,
velocity, time).
| 150
Return to Table of Contents
© 2019 College Board