A dog walks in a distance of a 100 feet in in 20 seconds of time what is the dogs speed in feet/second

Wooden , walls ,doors ,support

The answer is 4f======since electrostatic force is given by    we let f be the electrostatic force when  r = 1 m    if we let  denote the electrostatic force when the distance is decreased so that r = 0.5m, then    we established earlier that f = kq₁q₂. therefore    the force will now be 4f.

So are u adding some additional catalyst