Question

An iron ball and a feather are both dropped from a height of 20 m.
a) What are the time taken by the iron ball and feather to reach the ground?
b) What are the velocities of iron ball and feather when they reach the ground? (Ignore air resistance and take g = 10 m s-2)

Answer 1

Answer:

in freefall condition u=0 for both they take same time to reach on ground H=u×t+1/2gt^2 here u is zero and g is -g for directions purpose and h is 20 m so 20=-1/2×10×t^2 then t is 2 sec for both then velocity on reach the ground is also equal v=u+gt here g is negative and u is zero then v=-gt v=10×2 20 m/s and - is just show direction