Question

A flower pot falls off a window sill and falls past the window below. It takes 0.30s to pass a window 3.45 m high. How far is the top of the window below upper window sill?​

Answer 1

Given:

Time = t = 0.30 s

Distance = S =3.45 m

To find:

h =?

Explanation:

Let h be the height window sill from the ground.

An object is following down from the window.

∴ a = g =9.81

Now, the object is following down from 3.45 m high from the ground.

By using the third law of kinematical equation

S = ut + $\frac{1}{2 } \times at^2$

3.45 = u (0.30) + 0.5 × 9.81  ×0.30  × 0.30

u = 25.8924

∴ u = 25.89 m\s

Now consider the object is following down from the window sill.

v = 0 , s = h = ?

By the third law of kinematics:

$\displaystyle v^2 = u^2 + 2g(h)$

0 = 25.89 × 25.89 + 2 × 9.81 × h

h = -34.16 m

A negative sign shows that object is following down to the ground.

∴ h = 34.16 m

A window sill is 34.16 m high from the ground.