To calculate the kinetic energy of a ball, we can use the formula:
Kinetic energy (KE) = (1/2) * mass * velocity^2
Given: Mass (m) = 9 pounds Velocity (v) = 15 ft/s
First, let's convert the mass from pounds to slugs since the formula requires mass in slugs.
1 slug = 32.174 pounds
Mass (m) = 9 pounds / 32.174 pounds/slug ≈ 0.2799 slugs
Now we can calculate the kinetic energy:
KE = (1/2) * m * v^2 = (1/2) * 0.2799 slugs * (15 ft/s)^2 = 0.2799 slugs * 225 ft^2/s^2 ≈ 62.9775 ft-lb
Therefore, the kinetic energy of the ball is approximately 62.9775 ft-lb (foot-pounds).