Question 13 VCAA 2017 Sample Exam

[ScreaMy]

Does anyone have the answer to question 13: (Attached below) on the VCAA 2017 Sample Exam.
I had a look on the Itute answers but it said the mass wasn't given and also I'm not sure what they did, could you also explain what I was meant to do

Thanks

[TooLazy]

Does anyone have the answer to question 13: (Attached below) on the VCAA 2017 Sample Exam.
I had a look on the Itute answers but it said the mass wasn't given and also I'm not sure what they did, could you also explain what I was meant to do

Thanks

There are two ways you can work this out:

1. Calculate the initial kinetic energy. The total kinetic energy before the projectile hits the sea will be the intial kinetic energy PLUS the change in gravitational energy

2. Work out the final velocity of the stone (by calculating the resultant vector from the horziontal and vertical components of the final velocity).
   Then put this into the kinetic energy formula Ek=1/2mv^2

The 1st method is waaaaay quicker

[ScreaMy]

Ahhh cool thank a bunch

[TooLazy]

Ahhh cool thank a bunch

 I wouldnt mind a +1