A subatomic particle created in an experiment exists in a certain state for a time of $t=7\mathrm{.}3{10}^{-20}s$ before decaying into other particles. Apply both the Heisenberg uncertainty principle and the equivalence of energy and mass $($see Section $28\mathrm{.}6)$ to determine the minimum uncertainty involved in measuring the mass of this short$-$lived particle.

Number

i $1\mathrm{.}61e-28$

Units

kg