If the earth shrinks without any change in mass,how the length of the day will be affeced?

If the earth suddenly contrats to half of its original size without any change in mass,the new duration of the day would be :

If the earth suddenly shrinks (without chaging mass) to half its present radius, the value of g will be

Can force change only the direction of motion without any change in speed of an object? If yes, how?

If a wire is streched to double its original length without loss of mass, how will the resistivity of the wire be influenced?

If a wire is streched to double its original length without loss of mass, how will the resistivity of the wire be influenced?

A charged particle moving with a uniform velocity vecv enters a region where uniform electric and magnetic fields vecE and vecB are present. It passes through the region without any change in its velocity. What can we conclude about the relative direction of vecE , vecv and vecB?

Earth's orbit is an ellipse with eccentricity 0.0167. Thus, earth's distance from the sun and speed as it moves around the sun varies form day to day. This mean s that the length of the solar day is not constant through the year. Assume that earth's spin axis is normal to its orbital plane and find out the length of the shortest and the longesst day. A day should be taken from noon to noon. Does this explain variation of length of the day during the year?

A charged particle moving with a uniform velocity vecv enters a region where uniform electric and magnetic fields vecE and vecB are present. It passes through the region without any change in its velocity. What can we conclude about the magnitude of vecE and vecB ?

How does refraction of light affect the length of the day?