Question

A 20-pound object is dropped from a 50-foot bridge onto the ground below it. A 50-pound object is dropped from a 100-foot cliff onto the ground below it. Which object will hit the ground first? Support your answer with details.

Answer 1

Answer:

here 20 lb object will hit the ground first

Explanation:

Acceleration of the object while it is dropped in air is given as

$F = mg$

$a = \frac{F}{m}$

$a = g$

so acceleration of the object is independent of the mass of the object

now time to reach the ground is given as

$h = \frac{1}{2}gt^2$

$t = \sqrt{\frac{2h}{g}}$

for 20 pound object

$t_1 = \sqrt{\frac{2(50)}{32}}$

$t_1 = 1.77 s$

for 50 pound object

$t_2 = \sqrt{\frac{2(100)}{32}}$

$t_2 = 2.5 s$