Question

convert 1 km/h to the power -1 into 1 m/s to the power -1

Answer 1

1km/h=5/18m/s. it is also formula

Answer 2

km/h=1000*m/3600s
$1km \div h = (1000 \div 3600) \times m \div sec \\ so \: 1km \div h = (5 \div 18) \times m \div s$