In a playground, two slides have different angles of incline 1 and 2 (2 > 1). A

Question:

In a playground, two slides have different angles of incline θ1 and θ2 (θ2 > θ1). A child slides down the first at constant speed; on the second, his acceleration down the slide is a. Assume the coefficient of kinetic friction is the same for both slides.
(a) Find a in terms of θ1, θ2 , and g.
(b) Find the numerical value of a for θ1 = 45° and θ2 = 61°.