What are the questions choices?
Answer:
a) 2457J
b) 558W
c) 337N
Explanation:
Assuming dogs started from rest.

and the displacement is given by:

Using the energy conservation formula:

Because the motion started from rest the initial kinetic energy is zero, the motion occurred in-ground level so the gravitational energy is zero too.
the work done by the friction force is given by:

so:

The power is given by:

and the force exerted by the dogs:

Answer:
Explanation:
Assuming school is at the end of the 20 mile route, then
20 mi / 35 mi/hr = 0.57142...hr
which is about 34 minutes 17 seconds