F = 2 N
t = 2s
s = 20m
m=?
korzystamy z II zasady dynamiki: F = m * a obliczamy m:
[mat]m = \frac{F}{a}[/mat]
a obliczamy z wzoru: [mat]s = \frac{a * t^2}{2}[/mat]
2s = at^2
a = \frac{2s}{t^2} ; wstawiam do wzoru na m
m = F / 2s / t^2
[mat]m = \frac{F \cdot t^2}{2s}[/mat]
jednostki: [N] = \frac{kg*m}{s^2}
m = [ N*s^2/ m] = [kg*m/m] = [kg]