A 50-kg box of iron fishing weights is balanced at the edge of a table. Peter gives it a push and it falls 2 meters to the floor. Which of the following statements is true?

Question

A 50-kg box of iron fishing weights is balanced at the edge of a table. Peter gives it a push and it falls 2 meters to the floor. Which of the following statements is true??  
A. Once the box hit the floor, it lost its kinetic and potential energy.  
B. The box had kinetic energy when it was balanced at the edge of the table.  
C. The box had both kinetic and potential energy after it fell.  
D. Once the box hit the floor, it still had kinetic energy.

Accepted Answer

Correct Answer: (A)Once the box hit the floor, it lost its kinetic and potential energy.. 
Rationale: Once the box hit the floor, it lost both its kinetic and potential energy as these mechanical forms transformed into non-mechanical energy, heat, sound, and deformation, during the inelastic collision. At floor level with zero height and zero velocity, the box possesses neither gravitational potential energy nor kinetic energy in its final resting state.A) Once the box hit the floor, it lost its kinetic and potential energy.At floor level (h = 0), gravitational potential energy becomes zero. Upon impact, kinetic energy dissipates through inelastic collision processes, converting to thermal energy, sound waves, and floor/box deformation. While total energy conserves globally, the box loses its mechanical kinetic and potential energy components, making this statement physically accurate.B) The box had kinetic energy when it was balanced at the edge of the table.Kinetic energy requires motion (KE = ½mv²). While balanced motionless at the table edge, the box's velocity equals zero, yielding zero kinetic energy. It possessed gravitational potential energy due to height, but no kinetic energy until Peter's push initiated motion.C) The box had both kinetic and potential energy after it fell."After it fell" implies post-impact resting on the floor. At floor level, height h = 0 eliminates gravitational potential energy (PE = mgh). Assuming complete stop after impact, velocity v = 0 eliminates kinetic energy. The box possesses neither form of mechanical energy in its final resting state.D) Once the box hit the floor, it still had kinetic energy.Impact with an immovable floor typically produces an inelastic collision where kinetic energy dissipates rather than conserving. Unless the box rebounds (not indicated), its post-impact velocity equals zero, eliminating kinetic energy. Real-world collisions convert mechanical energy to other forms rather than preserving it.ConclusionA stationary object at height possesses gravitational potential energy but no kinetic energy. During free fall, potential energy converts to kinetic energy. Upon floor impact, both mechanical energy forms dissipate into non-mechanical forms, leaving the stationary box on the floor with neither kinetic nor potential energy, though total energy conserves globally through transformation.

A 50-kg box of iron fishing weights is balanced at the edge of a table. Peter gives it a push and it falls 2 meters to the floor. Which of the following statements is true?

A
Once the box hit the floor, it lost its kinetic and potential energy.

B
The box had kinetic energy when it was balanced at the edge of the table.

C
The box had both kinetic and potential energy after it fell.

D
Once the box hit the floor, it still had kinetic energy.

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Related Questions

A 50-kg box of iron fishing weights is balanced at the edge of a table. Peter gives it a push and it falls 2 meters to the floor. Which of the following statements is true?

A Once the box hit the floor, it lost its kinetic and potential energy. B The box had kinetic energy when it was balanced at the edge of the table. C The box had both kinetic and potential energy after it fell. D Once the box hit the floor, it still had kinetic energy.

Topic Flashcards

Mini Quiz

Related Questions

A
Once the box hit the floor, it lost its kinetic and potential energy.

B
The box had kinetic energy when it was balanced at the edge of the table.

C
The box had both kinetic and potential energy after it fell.

D
Once the box hit the floor, it still had kinetic energy.