Chapter 9, Problem 30P

Two average forces. A steady stream of 0.250 kg snowballs is shot perpendicularly into a wall at a speed of 4.00 m/s. Each ball sticks to the wall. Figure 9-49 gives the magnitude F of the force on the wall as a function of time t for two of the snowball impacts. Impacts occur with a repetition time interval Δt_r = 50.0 ms, last a duration time interval ∆t_d = 10 ms, and produce isosceles triangles on the graph, with each impact reaching a force maximum F_max = 200 N. During each impact, what are the magnitudes of (a) the impulse and (b) the average force on the wall? (c) During a time interval of many impacts, what is the magnitude of the average force on the wall?

Figure 9-49 Problem 30.