The ball is dropped from rest through a height of 4.5m.
(i) Assuming air resistance to be negligible, calculate the final speed of the ball.
[2]
(ii) A spherical ball of radius r experiences a resistive force F due to the air as it moves
through the air at speed v. The resistive force F is given by the expression.
F = crv,
where c is a constant
The ball has mass 15 g and radius 1.2 cm.
The numerical value of the constant c in the equation is equal to 3.2x104
when measured using the SI system of units
Show quantitatively whether the assumption made in (i) is justified
[3]