Mv + mv = 2mv providing each momentum is in the same direction.
1/2 mv^2 + 1/2 mv^2 = mv^2
Answer:
581 kJ, work was done by the system
Explanation:
According to the first law of thermodynamics:
where
is the change in internal energy of the system
Q is the heat absorbed by the system (positive if absorbed, negative if released)
W is the work done by the system (positive if done by the system, negative if done by the surrounding)
In this problem,
Therefore the work done by the system is
And the positive sign means the work is done BY the system.
<em>"A concave lens is thinner at the center than it is at the edges."</em>
If this isn't on the list of choices, that's tough. We can't help you choose the best one if we don't know what any of them is.
B. Impedes the flow of electrons
This next statement is a big deal. It should be up on a board, surrounded
by flashing red and yellow lights, and hung on the wall of every Science
classroom. Although we never see it in our daily lives, it's fundamental to
the workings of the universe, and it's also Newton's first law of motion:
<em>Without friction, it doesn't take <u>ANY</u> force to keep a moving object
moving. </em><em>Force is only required to <u>change</u> the object's speed, or to
<u>change</u> the direction </em><em>in which it's moving.</em>
The answer to the question is: On a level road, and neglecting any friction,
the engine doesn't have to supply ANY force to keep the car going at the
same speed.
