You're on a roll —
Step 1: Identify the given parameters for projectile motion.
Initial velocity, v0=40 m/s
Horizontal distance to the wall, x=10 m
Vertical height of the hole, y=7 m
Acceleration due to gravity, g=9.8m/s2 (standard value)
Step 2: Use the equations of projectile motion.
The horizontal distance is given by:
x=(v0cosθ)t
From this, we can express time t:
t=v0cosθx