A car move down a track a distance of 80 cm
Letter E 80 cm
Proportional
if the distance is proportional to the time square we can express such condition writing
d = k*t² (1)
where d is the distance t is the time and k is the constant of proportionality.
Now we must considerer that if the cart moves a distance of 20 cm in one second then by substitution in equation (1)
20 = k * (t)² ⇒ 20 = k*1 then k = 20
The proportionality constant is K = 20
To determine how far the cart move down in 2 seconds, again by substitution in equation (1) ( but now knowing k )
d = 20*(2)²
d = 20*4
d = 80 cm