formula for change in g due to change in longitude is
gchaned=g-rw2cos2x
where w= angular velocity of earth
1)ur question is wrong it shud have been latitude.u cant find change in g due to altitude unless u know the height.altitude 0f 45 will not give u any height.
2)3/5= 10 -6400w2cos0
ie 3/5=10-6400w2. find w and then v=rw=6400*w