Answer
$2.49\times 10^5\frac{mi}{h}$
Work Step by Step
According to given condition $P_{ball}=P_{car}$
implies: $P_{ball}=m_{ball}v_{ball}$
This can be rearranged as:
$v_{ball}=\frac{p_{car}}{m_{ball}}$
We plug in the known values to obtain:
$v_{ball}=\frac{15,800}{0.412}=1.11\times 10^6\frac{m}{s}$
Now we convert this speed in miles per hour as
$(1.11\times 10^6\frac{m}{s})(\frac{3600s}{h})(\frac{1mi}{1609m})=2.49\times 10^5\frac{mi}{h}$
