consider the velocity towards the pitcher as positive
m = mass of the baseball = 0.145 kg
v₀ = initial velocity of the baseball = - 39 m/s
v = final velocity of the baseball = 52 m/s
t = time of contact = 3 x 10⁻³ sec
F = average force between bat and ball
Using impulse-change in momentum equation
F t = m (v - v₀ )
F (3 x 10⁻³) = (0.145) (52 - (- 39))
F = 4398.33 N
