<span>None of the light passes through it; some of the light is absorbed as heat but most is reflected off the surface. This is how you see </span>objects. reflected light from them hits your eye. (Opaque means not transparent)
Taking right movement to be positive means leftward movement is negative.
Hence we have a deceleration of



Using this 'suvat' equation

we can determine the initial velocity



Hence the initial velocity is 13.0 meters per seconds

Actually Welcome to the Concept of the Projectile Motion.
Since, here given that, vertical velocity= 50m/s
we know that u*sin(theta) = vertical velocity
so the time taken to reach the maximum height or the time of Ascent is equal to
T = Usin(theta) ÷ g, here g = 9.8 m/s^2
so we get as,
T = 50/9.8
T = 5.10 seconds
thus the time taken to reach max height is 5.10 seconds.
Hooke's Law states that the extension is directly proportional to the force applied so:
F/x = constant
F₁/x₁ = F₂/x₂
2 / 0.02 = 1600 / x₂
x₂ = 16 m
Elastic work = 1/2 Fx
= 1/2 * 1600 * 16
= 12.8 kJ