I can't seem to figure this problem out. Please help!

__1. The problem statement, all variables and given/known data__A ball was launched upwards and vertically at a speed 3 m/second up to a height 4m. Calculate the mechanical energy of the ball if its weight is 5 Newtons and has a mass 0.5kg .

__2. Relevant equations__potential energy= mass x gravitational acceleration x height

kinetic energy= 1/2 mass x velocity x velocity

mechanical energy= potential energy + kinetic energy

__3. The attempt at a solution__mechanical energy = potential energy at maximum height

maximum potential energy =mass x gravitational acceleration x maximum height

= 0.5 x 10 x 4

= 20 joules

So, mechanical energy equals 20 joules?

Does this question seem right to everyone? I feel like there is a problem in the question itself. Does anybody else feel the same?

Many thanks,

Pamela Pepper