Answer:k=28.29 kN/m
Explanation:
Given
mass 
height from which Elevator falls 
Let x be the compression in the spring
thus From conservation of Energy Potential energy will convert in to Elastic Potential Energy of spring
----------1
also maximum acceleration is 5g
thus

here 


Substitute x in equation 1





Answer: 8 meters per second
Explanation: If you add 60 to 20 you get 80 meters and since he ran those 80 meters in 10 seconds you divide 80 by ten and get 8 and then you get 8m/s
Answer:


Explanation:
= Initial momentum of the pin = 13 kg m/s
= Initial momentum of the ball = 18 kg m/s
= Momentum of the ball after hit
= Angle ball makes with the horizontal after hitting the pin
= Angle the pin makes with the horizotal after getting hit by the ball
Momentum in the x direction

Momentum in the y direction


The pin's resultant velocity is 

The pin's resultant direction is
below the horizontal or to the right.