CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

From the top of a building of height $$40 m$$, a boy throws a stone vertically upwards with an initial velocity of $$10 m {s}^{-1}$$ such that it eventually falls to the ground. At what time will the stone reach the ground? $$\left( g=10m{ s }^{ -2 } \right) $$


A
4s
loader
B
3s
loader
C
2s
loader
D
1s
loader

Solution

The correct option is A $$4 s$$
$$s=−40m,u=+10m/s,a=−10m/s^2$$
Now $$s=ut+(1/2)at^2$$
=> $$−40=10t+1/2×(−10)t^2$$
=> $$t^2−2t−8=0$$
=> $$(t+2)(t−4)=0$$
=> $$t=−2,4s$$
The negative value of t is not possible
Hence the ball will hit the ground after $$4 s$$

Physics

Suggest Corrections
thumbs-up
 
0


similar_icon
Similar questions
View More


similar_icon
People also searched for
View More



footer-image