Resposta :
[tex]\Large \text {$ \sf 1) \dfrac {} {}$}\\\Large \text {$ \sf F = m.a \dfrac {} {}$}\\\Large \text {$ \sf 900 = m.4,5 \dfrac {} {}$}\\\Large \text {$ \sf 900 = 4,5m \dfrac {} {}$}\\\Large \text {$ \sf m = \dfrac {900} {4,5}$}\\\Large \text {$ \sf m = 200 kg \dfrac {} {}$}[/tex]
[tex]\Large \text {$ \sf 2) \dfrac {} {}$}\\\Large \text {$ \sf F = m.a \dfrac {} {}$}\\\Large \text {$ \sf F = 44.5 \dfrac {} {}$}\\\Large \text {$ \sf F = 220 N \dfrac {} {}$}[/tex]
[tex]\Large \text {$ \sf 3) \dfrac {} {}$}\\\Large \text {$ \sf F = m.a \dfrac {} {}$}\\\Large \text {$ \sf F = 20.5 \dfrac {} {}$}\\\Large \text {$ \sf F = 100 N \dfrac {} {}$}[/tex]