Answer:
The safety net should be 13.65 m away from the canon.
Step-by-step explanation:
The location for the safety net should be exactly at the position where the man will hit the ground.
This is a projectile motion.
We should separate the motion into x- and y-components, and investigate separately.
![v_0 = 11.6~m/s\\v_0_x = v_0\cos(42^\circ) = 8.62~m/s\\v_0_y = v_0\sin(42^\circ) = 7.76~m/s](https://img.qammunity.org/2021/formulas/physics/college/qydssqz87xtjr0k0475e8lihwvhj3lkedi.png)
On the x-direction, there is no acceleration, so the kinematics relations are
![x = v_0_x t = 8.62t](https://img.qammunity.org/2021/formulas/physics/college/ijnrqrkaqd1xzf8pxd170h25f6flu8xe4x.png)
On the y-direction, there is gravitational acceleration, -9.8. We will look for the time that takes for the man to hit the ground. The kinematics relations are
![y - y_0 = v_0_yt -(1)/(2)at^2\\0 - 0 = 7.76t - (1)/(2)9.8t^2\\0 = 7.76t - 4.9t^2\\t = 0 ~and ~ t = 1.58s](https://img.qammunity.org/2021/formulas/physics/college/mb3bto4hafb2j4rlm20h0lq5tjkv2yikwl.png)
Of course, we will not choose t = 0, since we know that t = 0 is the initial time.
We will plug this into the x-direction equation.
![x = 8.62t = 8.62*1.58 = 13.65~m](https://img.qammunity.org/2021/formulas/physics/college/q5sncapjf1jxb9gjxy1ut6b52chhbkkkch.png)