Explanation:
It is a good idea to start with room temperature water in the calorimeter because the room temperature water helps to determine the heating up/cooling down because of the environment as the experiment takes place. Because the calorimeter heat is the same as the heat of the water.
Answer:

Explanation:
From the question we are told that:
Bowling ball Speed 
Beach ball Speed 
Let The Mass be equal i.e

Therefore
Generally the equation for Velocity of beach ball after collision
is mathematically given by
Since Velocity is Vector Quantity
Therefore



Answer: There is not work done at the door because the door did not move.
Explanation: Work is defined as the movement done by a force.
So if you move to apply a force F in an object and you move it a distance D, the work applied on the object is
W = F*D
In this case, the secret agent pushes against the door, so there is a force, but the agent does not move the door, so D = 0, so there is no motion of the door, which implies that there is no work done at the door.
The second one is correct not sure about the first one sorry