Answer:Zero
Step-by-step explanation:
Given
mass of ball
![m=10\ kg](https://img.qammunity.org/2021/formulas/physics/high-school/re1dox6wkeebwa9qjdt147ui2ql6trw6en.png)
If the ball is thrown upward then at maximum point velocity of ball is zero because ball is no longer able to move upward
Momentum(P) of a particle is given by
![P=mass* velocity](https://img.qammunity.org/2021/formulas/physics/high-school/s44y0ipq6spj8e0jdczfilqgdl2o4y1shj.png)
![P=10* 0](https://img.qammunity.org/2021/formulas/physics/high-school/hdh8yumnzyrvsg8tsalm9fusv4l0a81658.png)
![P=0](https://img.qammunity.org/2021/formulas/physics/high-school/1d3e8y6wwa9gds2l8tjipjq4piq3lnjdoe.png)
Therefore at the highest point momentum is zero .