Aunt Gloria is cooling off an apple pie in her kitchen window when it is bumped and falls! If the window is 3.5m above the ground, what will be the velocity of the pie when it reaches the ground?

8.29 (m/s)

Explanation:

1. potential energy before the falling is:

where 'm' is mass of the pie; 'g' - is 9.81 N/kg; 'h' - is height of the window (h=3.5 m).

2. cinetic energy of the pie when it is reaching the ground is:

where 'm' is the mass of the pie; 'v' - the velocity of the pie when it is reaching the ground.

3. according to the condition

then

and

b.a device that inputs heat into a cool object