A shell bursts on contact with the gorund and pieces from it fly in all directions with velocities up to `60 m//s`. Show that a man `180 m` away is in danger for `6sqrt(2) s`.

Explanation

To solve the problem, we need to determine how long the man, who is 180 m away from the point of explosion, remains in danger from the pieces of the shell that burst with a maximum velocity of 60 m/s. We will use the concepts of projectile motion to find the time of flight for the pieces of the shell.

### Step-by-step Solution:

1. **Identify the parameters:**
- Maximum velocity of the pieces (u) = 60 m/s
- Distance from the explosion to the man (R) = 180 m
- We need to find the time duration (t) during which the man is in danger.
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