When a diamagnetic object is placed near one pole of a strong magnet, the object is repelled away from the pole by a magnetic force. if the magnet was held vertically and the magnetic force was strong enough, the object could levitate against the gravitational force. in 1997, researchers where able to produce a strong enough magnet that was able to levitate a small frog. they reasoned that since water is a diamagnetic material, with susceptibility x = -8.8 times 10-6, and that a frog is mostly water, the frog itself would be diamagnetic. they found that the magnetic force on the frog depended on the distance y above the magnet pole, where m is the frog's mass, the density of water rho = 1000 kg / m3, and the permeability of free space mu q = 4pi times 10-7 t m/a. the magnetic field b(y) above the magnet was measured to be, b(y) = b0e-y2/a with a = 0.00234 m2. in the experiment the frog levitate at a distance y0 = 0.0090 m above the magnet. what was the magnet's strength, b0, in their experiment? the earth's magnetic field is typically around 45 microteslas, how many times stronger is the magnet?