mathematics - Scale a normalized 2D vector always to the same length

For any normalized 2D vector, except for ( 0, 0 ), how would I scale the vector to always be the same length?

For example:

int length = 10;

vector v = vector( 0.1, 0.5 );
vector v2 = vector( 0.3, 0.8 );

// Scale v to be length of 10
// Scale v2 to be length of 10