Răspuns :

[tex]f = ma[/tex]

[tex]a = \frac{delta \: v}{delta \: t} = \frac{v2 - v1}{delta \: t} [/tex]

[tex]delta \: v = \frac{delta \: d}{delta \: t} \\ delta \: t = \frac{delta \: d}{v2 - v1} [/tex]

[tex]f = m \times \frac{(v2 - v1)}{1} \times \frac{(v2 - v1)}{delta \: d} [/tex]

[tex]f = \frac{m(v2 - v1) {}^{2} }{delta \: d} [/tex]

[tex]numeric \\ v2 = 50 \: \frac{km}{h} = 50 \times \frac{1000}{3600} = 13.8 \: \frac{m}{s} \\ v1 = 10 \: \frac{km}{h} = 10 \times \frac{1000}{3600} = 2.7 \: \frac{m}{s} [/tex]

[tex]f = \frac{500(13.8 - 2.7) {}^{2} }{100} \\ f = \frac{500 \times (1.1) {}^{2} }{100} \\ f = 5 \times 1.21 \\ f = 6.06 \: newton[/tex]