A child is pulling a wagon across the grass but friction between the grass and wheel creates a force in the opposite direction. If the wagon is speeding up, what does that mean about the two forces?

The slope of a velocity time graph over any interval of time gives the during that interval

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.

Can you match these to the correct definition