We are given that the system “releases” heat of 2,500 J,
and that it “does work on the surroundings” by 7,655 J.
The highlighted words releases and does work on the surroundings
all refers to that it is the system itself which expends energy to do those
things. Therefore the action of releasing heat and doing work has both magnitudes
of negative value. Therefore:
heat released = - 2, 500 J
work done = - 7, 655 J
Which means that the total internal energy change of the
system is:
change in internal energy = heat released + work
<span>change in internal energy = - 2, 500 J + - 7, 655 J</span>
<span>change in internal energy = -10,155 J</span>
Answer:
Explanation:Advatages
1..Its takes precise reading accurate
2. it is moveable because of its small weight
3.It is easy to read and can be kept inside water
Disadvantages
1. It breaks easily because of its small size
2. If broken there can be risk of exposure to mercury chemicals.
Answer:
Negative, because the speed is decreasing.
Friction
Friction also affects the movement of an object on a slope. Friction is a force that offers resistance to movement when one object is in contact with another. Imagine now that you were on the downside of the object and applying force to keep the object in the same place (not moving)
Answer:
Explanation:
Close to Earth's surface, the force of gravity that pulls an object towards the ground is
(2)
where
m is the mass of the object
g is the acceleration due to gravity, which is 
close to Earth's surface
This is an approximation of the general formula of gravity valid only close to Earth's surface. The more general formula is
(1)
where
G is the gravitational constant
M is the Earth's mass
m is the object's mass
r is the distance of the object from Earth's center
At the Earth's surface,
r = R (Earth's radius), and by calling the following factor
we see that eq.(1) becomes eq.(2).
