Conservation of Mechanical Energy

Steps:

• Ball starts with kinetic energy (KE) from throw and zero gravitational potential energy (PE) at ground.
• As it rises, height increases, so PE = mgh increases proportionally.
• Velocity decreases due to gravity, so KE = (1/2)mv² decreases.
• Total mechanical energy (KE + PE) remains constant, ignoring air resistance.

Why B is correct:

• By conservation of energy, decreasing KE converts to increasing PE as height rises, per E = KE + PE = constant.

Why the others are wrong:

• A: PE increases with height, does not decrease.
• C: KE decreases and PE increases, opposite of stated.
• D: Total energy is conserved and does not increase.

Final answer: B