Question

The ceiling of a classroom is 3.75 m above the floor. A student tosses an apple vertically upward, releasing it 0.5 m above the floor. What is the maximum initial speed that can be given to the apple if it is not to touch the ceiling?

Answer 1

h = 3.75 – 0.5 = 3.25 m
h = v(o) •t - g•t^2/2
v = 0 = v(o) - g•t.
v(o) =sqrt(2•g•h) = sqrt (2•9.8•3.25) = 7.98 m/s
v(o) < 7.98 m/s