An electron is located with an uncertainity equal to its uncertainity in velocity (symbols have usual meaning)?

An electron is located with an uncertainity equal to its uncertainity in its momentum. What will be its uncertainity in velocity (symbols have usual meaning)

Bohr magnetonis given by (symbols have their usual meanings)

The ratio of uncertainity in wave length and uncertainity in velocity is equal to

The ratio of uncertainity in wave length and uncertainity in velocity is equal to

Mechanically work done is equal to (symbols have their usual meanings)