The change in velocity is +4 m/s to the right (or -4 m/s to the left).
The object's mass is irrelevant.
 
        
             
        
        
        
Answer:
0.3 m
Explanation:
Initially, the package has both gravitational potential energy and kinetic energy.  The spring has elastic energy.  After the package is brought to rest, all the energy is stored in the spring.
Initial energy = final energy
mgh + ½ mv² + ½ kx₁² = ½ kx₂²
Given:
m = 50 kg
g = 9.8 m/s²
h = 8 sin 20º m
v = 2 m/s
k = 30000 N/m
x₁ = 0.05 m
(50)(9.8)(8 sin 20) + ½ (50)(2)² + ½ (30000)(0.05)² = ½ (30000)x₂²
x₂ ≈ 0.314 m
So the spring is compressed 0.314 m from it's natural length.  However, we're asked to find the additional deformation from the original 50mm.
x₂ − x₁
0.314 m − 0.05 m
0.264 m
Rounding to 1 sig-fig, the spring is compressed an additional 0.3 meters.
 
        
             
        
        
        
Force = mass x acceleration 
Force = 4kg x 10m/s^2
Force = 40N
        
             
        
        
        
Answer: Runofff
Explanation: because it said that it is going down the side of the mountain 
 
        
             
        
        
        
Nice paddling.  Thanks for sharing.
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