$1.$ Convert $4$km $/$ h to m $/$ s $.$ How many ft $/$ s in this $(20$ Points $)?2.$ Convert $1,500$ lb$.$ft to appropriate units $(20$ Points $).3.$ Evaluate each of the following and express with units having an appropriate prefix $(60$ Points$)$: a $.(600$mN$)($SGN$)$ b$.(500$mm$)*(0\mathrm{.}5$MN$)^2.50$M $*$ N $^3/1000*$ Gg