Without an external agent doing work, heat will always flow from a hotter to a cooler object. Two objects of different temperature always interact. There are three different ways for heat to flow from one object to another. They are conduction, convection, and radiation.
Answer:
The velocity is 
Henrietta is at distance
from the under the window
Explanation:
From the question we are told that
The speed of Henrietta is 
The height of the window from the ground is 
Generally the time taken for the lunch to reach the ground assuming it fell directly under the window is

=>
=>
Generally the time taken for the lunch to reach Henrietta is mathematically represented as

Here
is the time duration that elapsed after Henrietta has passed below the window the value is given as 4 s
Now
=>
Generally the distance covered by Henrietta before catching her lunch is

=> 
=> 
Generally the speed with which Bruce threw her lunch is mathematically represented as


Answer:
The net force is zero.
Explanation:
Two opposing and equal forces cancel each other out, giving you a net force of zero.
dissipation is the answer ;(