Newton's second law of motion:
F=ma
[tex]a = \frac{v}{t} [/tex]
You convert from km/h to m/s by dividing by 3.6:
[tex]v = 91 \div 3.6[/tex]
[tex]v = 25.3 \: \frac{m}{s} [/tex]
Then a is:
[tex]a = \frac{25.3}{9} [/tex]
[tex]a = 2.8 \frac{m}{s {}^{2} } [/tex]
Then:
F=(980)(2.8)=2744 N
