A copper ball sits in oil inside a cylinder closed by a piston of area $0.010\ \text{m}^2$. A $200\ \text{kg}$ mass is placed on the piston. By what fraction of itself does the ball's radius shrink? (Bulk modulus of copper $1.4 \times 10^{11}\ \text{Pa}$, $g = 9.8\ \text{m/s}^2$.)