If the polar ice capsmelted, how might this
effect the length of the day?

It will increase the length of the day

Explanation: The polar ice caps contain the solid ice particles found around the polar regions,an increased temperature is a major cause of the melting of the polar ice Caps. When the polar ice caps melt especially in huge volumes they increase the amount of water flowing into the Sea this will cause a rise in the volume of the sea.

This rise in sea level will add some weights to Earth, making the Earth to rotate slightly lower than its normal speed,a slower rotation will lead to longer days.

found in the nucleus

has mass of one amu

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west