## Exercise 2.5 A

Determine the length of the spring when there isn’t any mass suspended from it.

## Exercise 2.5 B

Define the mass of an unknown object.

## Exercise 2.5 C

Determine the value of acceleration due to gravity g with different lengths of a pendulum.

Tip 1: The oscillation time of a simple gravity pendulum is $T=2\pi\sqrt{\frac{l}{g}}$
Tip 2: Move the information to $(T^2,l)$ –coordinate system.
Answer: $9{,}9\ \frac{m}{s^2}$

## Exercise 2.5 D

Determine the position of the spring’s head as a function of time.

Tip: The waveform equation is a form $y=Asin(2\pi ft)$
Answer: $y=0,315\ m+0,05\ m\cdot\sin{\left(\frac{2\pi}{0,712\ s}\cdot\left(t-60{,}462\ s\right)\right)}$, where $t\geq60{,}462\ s$