At equator
g′=g−Rω2
=(9.8)2−(6400×103)(2π24×3600)2
=9.766m/s2
Now,mg=1000
∴m=1000g
w′=mg′=(1000)(g′g)
=(1000)(9.766)(9.8)
=997N
A 3 kg stone is weighed first at equator, then it is taken to the north pole. The weight measured by the spring balance will be