We get hurt when we jump on a muddy floor than on a hard floor. give reason

A muddy floor can be very slippery so if you jump on a muddy floor, you will most likely slip and hurt yourself.

A hard floor will most likely be dry. So when you jump on a hardwood floor, you are less likely to slip. But, you can hurt your knees if you're not careful.

Injury can occur

Explanation:

you might be running then you start jumping without putting your heels down, then might get achilles tendonitis in your achilles tendons.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it