Question

A particle falling under gravity displaces 80 ft in a certain second .How long does it take to displace 112 ft ? [g=32 ft/s^2]

Answer 1

Answer:

1 sec

Explanation:

Let us consider the velocity of particle when it completes 80 ft is V and this velocity will be initial velocity for 112 ft height. Let us consider it takes t time.

g=32ft/s  

2

 

V  

2

=u  

2

+2gh

V  

2

=O  

2

+2×32×80

V=  

64×80

​  

 

V=8×4  

5

​  

 

V=71.55 ft/s

now, h=vt+0.5×g×t  

2

 

112=71.55t+0.5×32×t  

2

 

On solving,

t=−h±  

h  

2

−4ac

​  

/2α

t=1 seconds