Mam can you please solve one math of physics chapter force and motion . The question is A stone dropped from the top of a building reaches the ground with the velocity of 49m/s .If acceleration due to gravity is 9.8m/s2 ,calculate the time for which stone a falling freely

Asked by prakritiranjankumar | 2nd Jul, 2020, 09:08: PM

Expert Answer:

A stone is dropped from a height of building. 
This means,
Initially the stone is at rest and
thus, 
Initial velocity, u = 0 
The stone reaches ground with velocity 49 m/s 
This means final velocity of the stone is, v = 49 m/s 
And the acceleration due to gravity,
a = g = 9.8 m/s2 
 
 first equation of motion is, 
v = u + at 
In case of freely falling bodies, 
first equation of motion becomes, 
v = u + gt 
Thus, 
49 = 0 + (9.8)× t 
49 = (9.8)t
 
t space equals space fraction numerator 49 over denominator 9.8 end fraction space equals space 5 space s 
Thus, time taken by stone to reach the ground is 5 seconds. 

Answered by Shiwani Sawant | 2nd Jul, 2020, 10:09: PM