Question

A ball is released from the top of a tower of height h meters. It takes T seconds to reach the ground. What it is the position of the ball at `"T"/3` second?

विकल्प

• `(8"h")/9` meters from the ground

• `(7"h")/9` meters from the ground

• `"h"/9` meters from the ground

• `(17"h")/18` meters from the ground

Answer 1

`bb((8"h")/9  "meters from the ground")`

Explanation:

We have s = `"ut"+1/2"gt"^2`

⇒ h = 0 × T + `1/2"gT"^2`

⇒ h = `1/2"gT"^2`

Vertical distance moved in time `"T"/3` is

h' = `1/2"g"("T"/3)^2`

⇒ h' = `1/2xx"gT"^2/9`

= `"h"/9`

∴ Position of a ball from ground = `"h"-"h"/9`

= `(8"h")/9`