Tony completed a 720 km journey with an average speed of 90 km for the first 285 km he travel about an average speed of 95 km what was the average speed for the remaining journey

Write the equation for momentum, first using symbols for the variables, then using words for the variables.

Idon’t quite understand this problem

Aperson walks first at a constant speed of 4.89 m/s along a straight line from point a to point b and then back along the line from b to a at a constant speed of 2.95 m/s. what is the average speed over the entire trip?