Question1
A 12.0kg shell is launched at an angle of 55.0 degrees above horizontal with an initial speed of 150 m/s. When it is at its highest point, the shell exploded into 2 fragments, one three times heavier than the other. The two fragments reach ground at the same time. Assume that air resistance can be ignored. If the heavier fragment lands back at same point from which the shell was launched, where will the lighter fragment land and how much energy was released in the explosion?
Question2
Consider two conducting spheres with radii R1 and R2 separated by a distance much greater than either radius. A total charge Q is shared between the spheres. We wish to explain that when the electric potential energy of system has a minimum value, potential difference between the spheres is zero. The total charge Q is equal to q1 + q2, where q1 represents charge on the first sphere and q2 the charge on the second. Since the spheres are very far apart, you can suppose the charge of each is uniformly distributed over its surface.