Question

A key falls from a bridge that is 32 m above the water. It falls directly into a model boat, moving with constant velocity, that was 11 m from the point of impact when the key was released. What is the speed of the boat?

Answer 1

Speed of the boat, v = 4.31 m/s

Step-by-step explanation:

Given that,

Height of the bridge, h = 32 m

The model boat is 11 m from the point of impact when the key was released, d = 11 m

Firstly, we will find the time needed for the boat to get in this position using second equation of motion as :

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

Here, u = 0 and a = g

`t=\sqrt{(2s)/(g)}`

`t=\sqrt{(2* 32)/(9.8)}`

t = 2.55 seconds

Let v is the speed of the boat. It can be calculated as :

`v=(d)/(t)`

`v=(11\ m)/(2.55\ s)`

v = 4.31 m/s

So, the speed of the boat is 4.31 m/s. Hence, this is the required solution.