A golf ball of mass 0.05 kg struck by a golf club of mass 𝑚 kg with speed 50 𝑚/𝑠 will have an initial speed of u(m) =
83m/m+0.05. Verify that u'(m) > 0. Compare u'(0.15) and u'(0.20) in terms of the speed and mass of the ball.
u(m) = 83m/m+0.05.
still makes no sense. Maybe some parentheses?
If u(m) = 83m/(m + 0.05) then
u'(m) = 4.85/(m+0.05)^2
which is always positive.