Stone drops from the edge of the roof- It passes window 2 m high in 0-15- How far is the roof above the top of the window-

Height of the window (h) = 2m Acceleration due to gravity g = 9.8 m/s^2 Time taken (t) = 0.1 s The velocity of the stone when it reaches the top of the window i ...

You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard IX

Physics

Equations of Motion

Stone drops f...

Question

Stone drops from the edge of the roof. It passes window 2m high in 0.1 sec. How far is the roof above the top of the window? $(t a k e g = 10 m / s^{2}$ )

Open in App

Solution

Height of the window (h) = 2m
Acceleration due to gravity $g = 10 m / s^{2}$
Time taken (t) = 0.1 s
The velocity of the stone when it reaches the top of the window is to be calculated.
Applying the second equation of motion,
$h = u t + \frac{1}{2} a t^{2}$
$2 = u (0.1) + 5 (0.01)$
$(0.1) u = 1.95$
$U = 19.5 m / s$
Thus, the velocity 19.5 m/s will be the final velocity as soon as the stone starts covering the distance between the roof and the upper edge of the window.
As stone starts from rest i.e., u = 0
$v^{2} - u^{2} = 2 g h$
$(19.5)^{2} - 0 = 20 h$
$\Rightarrow h = 19.01 m$
Distance between the roof and upper edge of the window = 19.01 m.

Suggest Corrections

119

Similar questions

Q. A stone is dropped from the of the roof.It passes a window 2m high 0.1s.How far is the roof above above the window? (g=10 m/s²)

Q. A ball is dropped from the edge of a roof. It takes

0.1 s

to cross a window of height

2.0 m

. Find the height of the roof above the top of the window.

Q. A ball dropped from one metre above the top of a window, crosses the window in

t_{1} s

. If the same ball is dropped from

2 m

above the top of the same window, time taken by it to cross the window is

t_{2} s

. Then

A steel ball is dropped from a building's roof and passes a window of lenght $10 m$ , taking $1 s$ to fall from the top of the window to the bottom of the window. It then falls onto a sidewalk and bounces back past the window, moving from bottom to top in $1 s$ . Assume that the upward flight is an exact reverse of the fall. The time the ball spends below the bottom of the window is $2 s$ . How tall is the building?

Q. A flower pot falls off a window sill and falls past the window below. It takes

0.5 s

to pass through a

2.0 m

high window. Find how high is the window sill from the top of the window?

Join BYJU'S Learning Program

Stone drops from the edge of the roof. It passes window 2m high in 0.1 sec. How far is the roof above the top of the window? (takeg=10m/s2)

Stone drops from the edge of the roof. It passes window 2m high in 0.1 sec. How far is the roof above the top of the window? $(t a k e g = 10 m / s^{2}$ )