Given:
Initial velocity, u = 80î + 60ĵ m/s

To find:
The maximum height reached by the body

Assumptions:
- The body is thrown vertically upwards.
- The only force acting on the body is gravity.
- Air resistance is negligible.

Analysis:
When the body is thrown upwards, it experiences a downward force due to gravity which causes it to decelerate. At the highest point, the body momentarily comes to rest before falling back down.

Let's analyze the motion of the body in two parts:

1. Vertical Motion:
The vertical component of the initial velocity is given by v₀ = 60 m/s.

Using the equation of motion:
v² = u² + 2as

where v = final velocity (0 m/s at maximum height), u = initial velocity, a = acceleration (due to gravity), and s = displacement (maximum height)

Substituting the given values:
0² = 60² + 2(-9.8)s
0 = 3600 - 19.6s
19.6s = 3600
s = 183.67 m

Therefore, the maximum height reached by the body is 183.67 meters.

2. Horizontal Motion:
Since there is no force acting horizontally, the horizontal component of velocity remains constant throughout the motion.

The horizontal component of the initial velocity is given by u = 80 m/s.

Therefore, the body will continue to move horizontally with a constant velocity of 80 m/s.

Conclusion:
The body reaches a maximum height of 183.67 meters and continues to move horizontally with a constant velocity of 80 m/s.