A 0.15-kg ball is thrown into the air and rises to a height of 20.0 m. How much kinetic energy did the ball initially have?

IF the toss was straight upward, then the kinetic energy it got

from the toss is the gravitational potential energy it has at the top,

where it stops rising and starts falling.

Potential energy = (mass) x (gravity) x (height)

= (0.15 kg) x (9.8 m/s²) x (20 m)

= 29.4 kg-m²/s² = 29.4 joules.