I’m gonna have to say “Ocean waves” as the answer
        
                    
             
        
        
        
Answer:
225 N
Explanation:
"Below the horizontal" means he's pushing down at an angle.
Draw a free body diagram of the box.  There are three forces: normal force N pushing up, weight force mg pulling down, and the applied force F at an angle θ.
Sum of forces in the y direction:
∑F = ma
N − mg − F sin θ = 0
N = F sin θ + mg
Plug in values:
N = (50 N) (sin 30°) + (20.0 kg) (10 m/s²)
N = 225 N
 
        
             
        
        
        
31 m/s ÷ 9 m/s² = 3.44 s
Time = Change in velocity divided (÷) by acceleration.
 
        
             
        
        
        
Answer:
Bok.............................