Question

a ball dropped from a height h reaches the ground in time T what is height at timeT/2​

Answer 1

For a freefall,

Acceleration ,  a=gm/s2  

Initial velocity ,  u=0m/s  

Let the distance travelled by the ball be x.

Applying second equation of motion,

s=ut+(1/2)at2  

x=0+(1/2)gt2  

Substituting the the value of t as (T/2),

x=(1/2)g(T2/4)  

{ As per the question,

h=(1/2)gT2  

Find out the value of T from the above expression and put it. }

This implies,  x=h/4  .

Now, the height of the ball from the ground will be equal to (h - x).

Therefore  (3h)/4  is the required answer.

Answer 2

A ball dropped from a height "h" reaches the ground in time T. What is the height of the ball at the time (T/2)?

A2A

For a freefall,

Acceleration , a=gm/s2

Initial velocity , u=0m/s

Let the distance travelled by the ball be x.

Applying second equation of motion,

s=ut+(1/2)at2

x=0+(1/2)gt2

Substituting the the value of t as (T/2),

x=(1/2)g(T2/4)

{ As per the question,

h=(1/2)gT2

Find out the value of T from the above expression and put it. }

This implies, x=h/4 .

Now, the height of the ball from the ground will be equal to (h - x).

Therefore (3h)/4 is the required answer.

Hope this helps.

-KB