Question

a ball is dropped from the top of a tower the distance travelled by the ball in the last second is 40 m.find height of tower​

Answer 1

Answer:

as acceleration is constant then by formula.

s=a/2(2n-1).

where ,

a=10

and

s=40

so10/2(2n-1)=40.

so n=4.5sec.

now a=10.

u=0.t=4.5

so.

s=ut +1/2at^ s=5*4.5*

4.5=101.25 m

Step-by-step explanation:

Answer 2

Answer:

Let h = the height of the tower that needs to be determined.

Let t be the time of fall.

Then (t - 2) would be the time to reach the top of the 40 meter mark, and let d be the distance fallen till it reaches the 40 m mark.

Using kinematics, we can write:

d=

2

1

g(t−2)

2

And H=1/2gt

2

H also =40+d

Then: H=40+1/2g(t−2)

2

=1/2gt

2

40+5t

2

−20t+20=5t

2

t=3s

(t−2)=1second

In one second an object falls 5 m

Then H=45m