A 0.50 kg ball is dropped from rest from a balcony 2.5 m above the ground
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Work Energy and Power · Work Energy and Power
Problem
A 0.50 kg ball is dropped from rest from a balcony 2.5 m above the ground. Immediately before the ball hits the ground it passes through an electronic sensor that records its kinetic energy, but the display malfunctions. A pre-programmed energy bar chart for the ball–Earth system at two positions is stored in memory and is summarized below.
Position 1 (just after release):
• Gravitational potential energy bar height: 5 relative units
• Kinetic energy bar height: 0 relative units
Position 2 (just before impact):
• Gravitational potential energy bar height: 0 relative units
• Kinetic energy bar height: 5 relative units
Assume no air resistance.
(a) Determine the numerical value (in joules) that corresponds to one relative unit on the bar chart.
(b) Using your result from part (a), calculate the magnitude of the ball’s kinetic energy immediately before impact.
(c) Determine the ball’s speed immediately before impact.
(d) If a light breeze exerted a small upward force on the ball during its fall, describe qualitatively how the bar chart for Position 2 would change and explain your reasoning.