A ball is thrown upward from an 80-ft tower with an initial vertical speed of 40 ft/s.If air resistance is ignored,the ball's speed when it reaches the ground will be A)67 ft/s B)1.3 $\times$ 10² ft/s C)1.2 $\times$ 10² ft/s D)49 ft/s E)82 ft/s

Question

Quizplus · Accepted Answer

The ball's speed when it reaches the ground can be found using the conservation of energy or kinematic equations. The initial potential energy and kinetic energy convert into kinetic energy at the ground. Using the equation v² = u² + 2gh, where u is the initial speed (40 ft/s), g is the acceleration due to gravity (32 ft/s²), and h is the height (80 ft), the final speed v is approximately 82 ft/s.

A Ball Is Thrown Upward from an 80-Ft Tower with an Initial