Two workers must slide a crate designed to be pushed with a rigid rod (on the left in Fig. P4.73) and at the same time pulled with a rope (on the right). The crate has mass m = 45 kg, the angle θ = 25º, and the coefficient of kinetic friction between the floor and crate is 0.56. One of the workers (named Joe) can exert a force of 160 N, while the other (Paul) can exert a force twice that large. If we want to move the crate as quickly as possible, is it better to have the stronger worker (Paul) push and the weaker worker (Joe) pull, or vice versa? Does it matter? Calculate the acceleration for both cases to find out.

Figure P4.73

Rigid rod Rope This worker This worker pushes. pulls.