Answer:
In physics, work is the amount of energy required to perform a given task (such as moving an object from one point to another). We start by defining the scalar product of two vectors, which is an integral part of the definition of work, and then turn to defining and using the concept of work to solve problems.
Answer:
Between 2.0 s and 4.0 s (B and C)
Between 5.0 s and 8.0 s (D and E)
Between 10.0 s and 11.0 s (F and G)
Explanation:
The graph shown in the figure is a velocity-time graph, which means that:
- On the x-axis, the time is plotted
- On the y-axis, the velocity is plotted
Therefore, this means that the object is not moving when the line is horizontal (because at that moment, the velocity is constant, so the object is not moving). This occurs in the following intervals:
Between 2.0 s and 4.0 s (B and C)
Between 5.0 s and 8.0 s (D and E)
Between 10.0 s and 11.0 s (F and G)
From the graph, it would be possible to infer additional information. In particular:
- The area under the graph represents the total distance covered by the object
- The slope of the graph represents the acceleration of the object
Answer:
0.245
Explanation:
When the block is released, the initial elastic potential energy stored in the spring is entirely converted into kinetic energy of the block.
Therefore, we can calculate the initial speed of the block:
where the term on the left is the potential energy and where the term on the right is the kinetic energy, and where
k = 4500 N/m is the spring constant
x = 8.0 cm = 0.08 m is the compression of the spring
m = 3.0 kg is the mass of the block
v is the initial velocity
Solving for v,
Then, after the block is released, all its kinetic energy is converted into thermal energy as the block slows down, due to friction. Therefore, the work done by friction is equal to the initial kinetic energy of the block.
The force of friction is
where
is the coefficient of friction
is the acceleration of gravity
So the work done by it is (in magnitude)
where
d = 2.0 m is the distance covered
Therefore,
And solving for ,
Nitrogen could form 3 bonds based on octet rule, because it has 5 valence electrons. That means it needs 3 bonds.
Explanation:
- A nitrogen atom can fill its octet by sharing three electrons with another nitrogen atom, forming three covalent bonds, a so-called triple bond.
- A triple bond isn't quite three times as strong as a single bond, but it's a very strong bond.
- Every covalent bond is a sharing of two electrons between two atoms. A double bond is 4 electrons being shared (2x2). Therefore a triple bond is 6 electrons being shared (2x3)
- Triple bonds are stronger than double bonds due to the the presence of two pi bonds rather than one.
- Each carbon has two sp hybrid orbitals, and one of them overlaps with its corresponding one from the other carbon atom to form an sp-sp sigma bond.
- A single lone pair can be found with atoms in the nitrogen such as nitrogen in ammonia , two lone pairs can be found with atoms in the chalogen group such as oxygen in water and the halogen can carry three lone pairs such as in hydrogen chloride. Nitrogen has 2 lone pairs.
