Answer
$r=0.59m$
Work Step by Step
We know that:
$KE=\frac{1}{2}mv^2$
This simplifies to
$v=\sqrt{\frac{2KE}{m}}$........ eq(1)
We also know that
$r=\frac{mv}{qB}$
Substituting value of "v" from equation (1), we obtain:
$r=\frac{m\sqrt{\frac{2KE}{m}}}{qB}$
$r=\frac{\sqrt{2(KE)m}}{qB}$
We plug in the known values to obtain:
$r=\frac{\sqrt{2(1.5\times 10^6)(1.6\times 10^{-19})(1.67\times 10^{-27})}}{1.6\times 10^{-19}(0.3)}$
$r=0.59m$
