Two identical conducting spheres, one that has an initial charge +Q, the other initially uncharged, are brought into contact. While the spheres are in contact, a positively charged rod is moved close to one sphere, causing a redistribution of the charges on the two spheres so the charge on the sphere closest to the rod has a charge of -Q. What is the charge of the other sphere?

The new charge is

Explanation:

From the question we are told that

The initial charge of the first one is

The charge on the sphere closest to the rod is

Generally at the point the charge was redistributed the charge on each sphere is

Also from the question we are told that the new charge on one of the sphere is -Q

So this mean that

Here k is the charge on the other sphere

=>      

truck y has a greater velocity than truck x.