Answer:
Equation: 10t=400
It will take them 40 hours to be 400 miles apart.
Explanation:
Constant Speed Motion
If the speed of an object is v, the distance traveled in a time t is:
![x=v\cdot t](https://img.qammunity.org/2021/formulas/physics/high-school/9hh88xbkwlvw78hn2bzfk12ui5krllpcnx.png)
Ms. Ironperson travels at 50t (not speed, but a distance), and Mr. Thoro travels at 60t. Since the latter travels faster, the distance between them at time t is given by:
![D=60t-50t=10t](https://img.qammunity.org/2021/formulas/mathematics/college/rf1xtleikgn4blo2bsupai1x9byu74u0op.png)
To be 400 miles apart, we set the equation:
10t=400
Solving:
t=400/10=40
It will take them 40 hours to be 400 miles apart.
Note: Some assumptions were made in this question:
- The rates are not speeds but distances
- The distances are in miles