F1 * D1 = F2 * D2

F1 = ?

D1 = Distance between F1 and fulcrum

F2 = Weight of 200kg mass

D2 = Distance between Mass and fulcrum

Figure out D1, F2 and D2 (in meters and newtons) to find F1

D1 = 1.5m - 50mm

D1 = 1.5m - (50mm)(1m/1000mm)

D1 = 1.5m - .05m

D1 = 1.495m

F2 = Weight of 200Kg = 200N

D2 = 50mm

D2 = (50mm)(1m/1000mm)

D2 = .05m

Now use the initial equation: F1 * D1 = F2 * D2

F1 * 1.495m = 200N * .05m

F1 = (200N * .05m)/1.495m

F1 = 6.69 Newtons