g = 9.8 N kg-1
density of water = 1000 kg m3
dimensions of wooden block = 50 cm × 50 cm × 50 cm
= 0.5 m × 0.5 m × 0.5 m [converting to metres]
Volume of wooden block = 0.5 m × 0.5 m × 0.5 m
= 0.125 m3
Buoyant force = volume of block × density of water × g
= 0.125 × 1000 × 9.8
= 1225 N