Your answer is 142.86 milliseconds rounded to two decimal places.
As 1 second is equal to 1000 milliseconds, we can write the ratio 7:1000 to represent feet to milliseconds. We can then see that to get 1 foot, we just have to divide 1000 by 7, which gives us 142.8517, or 142.86 to two decimal places.
I hope this helps!
