an object of mass 100kg is released from a height of 4m.calculate it's kinetic energy just before it hits the ground.take g=10m/s

Answer 1

The KE will equal the max PE at which it started.
KE=mgh=100*g*4 joules

g is not 10m/s^2 anywhere on Earth. Fire your teacher for teaching you that. Use 9.81m/s^2