Question

how to do this A young vandal wishes to hit a truck traveling at a constant speed of 20m/s with a water balloon. If the vandal is in a tree, 40 m from the top of the truck, how far should the truck be from the tree when she releases the balloon so that it hits the truck when it is at a position directly beneath her?

Answer 1

6.89 m

Step-by-step explanation:

t = Time taken

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration

`s=ut+(1)/(2)at^2\\\Rightarrow 40=0* t+(1)/(2)* 9.81* t^2\\\Rightarrow t=\sqrt{(40* 2)/(9.81)}\\\Rightarrow t=2.9\ s`

The water balloon will take 2.9 seconds to hit the tree

As, the truck is moving at a constant speed of 20 m/s it does not have acceleration

`s=ut+(1)/(2)at^2\\\Rightarrow s=20* 2.9+(1)/(2)* 0* t^2\\\Rightarrow s=6.89\ m`

The boy has to release the balloon when the truck is 6.89 m away