Question

A ball falls off a table and reaches the ground in 1 s. Assuming g = 10 m/s², calculate its speed on reaching the ground and the height of the table. 

Answer 1

Here, t =1 s

g = 10 m/s²

u = 0

Let v be the velocity of the ball on reaching the ground.

Thus, from first equation of motion, we have

v = u + gt

⇒ v = 10 x 1 = 10 m/s

Hence, the speed of the object on reaching the ground is 10 m/s.

Let h be the height of the table. Thus, from the second equation of motion, we have 

`"S" = "ut" + 1/2 "gt"^2`

`⇒ "h" = 0 + 1/2 xx 10xx1^2`

⇒ h = 5 m 

Hence, the height of the table is 5 m.