# Homework Help: Heisenberg Uncertainty Principle and Kinetic Energy

1. Mar 30, 2010

### tatiana_eggs

1. The problem statement, all variables and given/known data

18. A ball of mass 50 g moves with a speed of 30 m/s. If its
speed is measured to an accuracy of 0.1%, what is the
minimum uncertainty in its position?

19. A proton has a kinetic energy of 1.0 MeV. If its momentum
is measured with an uncertainty of 5.0%, what is
the minimum uncertainty in its position?

2. Relevant equations
$$\Delta$$p$$\Delta$$x $$\geq$$$$\frac{h}{4\pi}$$

3. The attempt at a solution
I know how to solve #19, because I know that $$\Delta$$p / p = uncertainty. But what about accuracy? Do they mean the same thing? How does accuracy relate to $$\Delta$$p or $$\Delta$$x or the uncertainty of one of those?

Thanks!

2. Mar 30, 2010

### nickjer

I believe they mean the same thing with accuracy.