We would need to know the time it took to slow to a stop.
Answer:
v=0.816 m/s
Explanation:
The force of the spring and the motion of the block are in equilibrium so without any force of friction the motion is


First determinate the constant of the spring that produce the kinetic energy of the bloc



Now the motion with the force of friction in the kinetic


Resolve to v



Answer:
Explanation:
Given
Initial velocity of ball 
height of window 
Using Equation of motion

where u=initial velocity
t=time
a=acceleration
As ball is already is at a height of 20 m so



(b)highest point is obtained at v=0

where
v=final velocity
u=initial velocity
a=acceleration
s=displacement



Highest Point will be 
(c)Time taken when the ball hit the ground i.e. at Y=0


impact velocity 
A pigment absorbs some colors of light and reflects other colors.
hope this helps!
Scientific journals are a place for the scientists to share the results of their work. Without them, it could happen that all the scientists would work on the same problems, without knowing that someone else has already solved this problem. With the journals, they can instead focus on furthering our knowledge, and not repeating the basic experiments.