Question

Aunt Matilda goes to a well and throws a penny straight down the well at 3.0 m/s. She hears a splash after 0.5 seconds. How deep is the well? a) 0.31 m b ) 0.91 m c) 1.54 m d) 2.73 m e) 5.30 m

Answer 1

Answer : The correct option is (d) 2.73 m

Explanation :

By the 2nd equation of motion,

`s=ut+(1)/(2)at^2`

where,

s = distance or height = ?

u = initial velocity = 3.0 m/s

t = time = 0.5 s

a = acceleration due to gravity =
`9.8m/s^2`

Now put all the given values in the above equation, we get:

`s=(3.0m/s)* (0.5s)+(1)/(2)* (9.8m/s^2)* (0.5s)^2`

`s=2.73m`

Therefore, the correct option is (d) 2.73 m