Question

An object is dropped from a platform 100 feet high. Ignoring wind resistance, how long will it take to reach the ground? _____ s

Answer 1

Height of the platform = 100 feet

1 feet = 0.3048 m

100 feet = 30.48 m

Acceleration due to gravity (g) = 9.8 m/s^2

Let the time taken be t

Initial velocity of the object (u) = 0 m/s

Using the seconds equation of motion:

$s = ut + \frac{1}{2}at^2$

$30.48 = 0 + \frac{1}{2}\times 9.8 \times t^2$

$t = \sqrt{\frac{30.48}{4.9} }$

t = 2.5 seconds

Hence, the option (b) is correct.

Answer 2

Answer:

Answer B is correct.

Explanation: