Federpendel - harmonische Schwingungen / schräger Wurf

Hey, also ich habe 2 Aufgaben die ich gerade nicht verstehe.
Hoffe ihr könnt mir helfen.
Die Aufgaben sind leider aber in Englisch da ich gerade ein Austauschajhr mache und hier halt noch bisschen probleme mit mathe hab.

1)Consider a weight hanging from a spring.
Call the initial position of the weight the orgin.
The weight is pulled down a distance of a cm from the origin and released. If we ignore the effects of friction and wind resistance=, the resulting motion is called simple harmonic motion, and can be modelled by the function s=a cos bt, where a is the amplitude, and b is releated to the stiffness of the spring.

b) What is the period and ampltude of this periodic function?

c)Where is the weight after 1 second?

d)Find the expression for the velocity at time t seconds?

e)What is the velocity after 1 second?

f)When is the velocity first zero?

g)What is the displacement at that time?

h)Find an expression for the acceleration at time t seconds.

i)When is the acceleration zero? Where is it at this time?






zweite Aufgabe

If a ball is hit into the air at an angle of elevation between 0 and 90 degrees its path can be modelled by the equation y= sin θ gx2 (is ist im quadrat )
______ - ______

cos θ 2u 2 cos 2 θ ( die zweite 2 und dritte sind im Quadrat)

where x and y are cartesian coordinates,

g= 10 m/s2 (im Quadrat), u= (initial velocity), θ =the angle of projection.
The velocity is 40 m/s and the boundary is 70 m from the pitch.
Is he capable of hitting it there and if so calculate the angle at which the ball should be hit to the clear the boundary rope.
( ie. y=0 and x= 70

Hoffe es ist nicht zu viel und hoffe auch ihr könnt mir helfen.