Cuesta College, San Luis Obispo, CA
Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Problems 7.43, 7.44
A 0.0036 kg Nosler® Ballistic Tip V-Shok .223 Remington bullet[*] is shot horizontally with a speed of 988 m/s and collides into a 2.6 kg block of wood. The bullet embeds itself in the block, and the block with embedded bullet together slide along a horizontal frictionless surface. What is the final kinetic energy of the sliding block and embedded bullet system? Show your work and explain your reasoning using properties of collisions, energy (non-)conservation, and momentum conservation.
Solution and grading rubric:
Correct. Applies momentum conservation to the perfectly inelastic collision between bullet and block to find the final velocity of bullet/block, and then calculates the final kinetic energy of bullet/block.
Nearly correct, but includes minor math errors. Momentum conservation applied to successfully find the final velocity of bullet/block, problematic kinetic energy calculation.
Nearly correct, but approach has conceptual errors, and/or major/compounded math errors. Only momentum conservation applied to successfully find the final velocity of bullet/block. No kinetic energy calculation.
Implementation of right ideas, but in an inconsistent, incomplete, or unorganized manner. Garbled attempt at momentum conservation, may or may not have kinetic energy calculation.
Implementation of ideas, but credit given for effort rather than merit. Does not apply momentum conservation.
Irrelevant discussion/effectively blank.
Sections 70854, 70855
Exam code: midterm02fR3q
p: 24 students
r: 4 students
t: 5 students
v: 8 students
x: 7 students
y: 0 students
z: 0 students
A sample "p" response (from student 4816):