Answer:
d = 2.54 [m]
Explanation:
Through the theorem of work and energy conservation, we can find the work that is done. Considering that the energy in the initial state is only kinetic energy, while the energy in the final state is also kinetic, however, this is zero since the body stops.

where:
W = work [J]
Ek1 = kinetic energy at initial state [J]
Ek2 = kinetic energy at the final state = 0.
We must remember that kinetic energy can be calculated by means of the following expression.
![\frac{1}{2} *m*v^{2}-W=0\\W= \frac{1}{2} *4*(5)^{2}\\W= 50 [J]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D-W%3D0%5C%5CW%3D%20%5Cfrac%7B1%7D%7B2%7D%20%2A4%2A%285%29%5E%7B2%7D%5C%5CW%3D%2050%20%5BJ%5D)
We know that work is defined as the product of force by distance.

where:
F = force [N]
d = distance [m]
But the friction force is equal to the product of the normal force (body weight) by the coefficient of friction.
![f=m*g*0.5\\f = 4*9.81*0.5\\f = 19.62 [N]](https://tex.z-dn.net/?f=f%3Dm%2Ag%2A0.5%5C%5Cf%20%3D%204%2A9.81%2A0.5%5C%5Cf%20%3D%2019.62%20%5BN%5D)
Now solving the equation for the work.
![d=W/F\\d = 50/19.62\\d = 2.54[m]](https://tex.z-dn.net/?f=d%3DW%2FF%5C%5Cd%20%3D%2050%2F19.62%5C%5Cd%20%3D%202.54%5Bm%5D)
Answer:

Solution:
As per the question:
Point charge, q = 
Test charge, 
Work done by the electric force, 
Now,
We know that the electric potential at a point is given by:

where
r = separation distance between the charges.
Also,
The work done by the electric force i moving a test charge from point A to B in an electric field:




Answer:
1.7×10^5 ms-1
Explanation:
From
qE= qvB
q= charge on the electron
E = electric field
v= velocity
B= magnetic field
E= vB
v= E/B= 110×10^3/0.6
v= 1.7×10^5 ms-1
Explanation:
Matter is changed from one state to another by addition or removal of heat and suitable pressure conditions.
When a solid is heated, it normally melts and changes to liquids which on heating changes to vapor. The randomness of the particles increases from solid to liquid state and to gaseous states.
Also, a gas can be cooled to liquid and on further cooling transformed into a solid matter.
These phase changes are brought about by energy changes in a system. Some form of matter can also sublime by changing form solid to gas and vice versa.
This means that we shouldn't imagine electrons as single objects going around the atom. Instead, all we know is the probability of finding an electron at a particular location. What we end up with is something called an electron cloud. An electron cloud is an area of space in which an electron is likely to be found. It's like a 3-D graph showing the probability of finding the electron at each location in space. Quantum mechanics also tells us that a particle has certain numbers (called quantum numbers) that represent its properties. Just like how materials can be hard or soft, shiny or dull, particles have numbers to describe the properties. These include a particle's orbital quantum numbers, magnetic quantum number, and its spin. No two electrons in an atom can have exactly the same quantum numbers. Orbital quantum numbers tell you what energy level the electron is in. In the Bohr model, this represents how high the orbit is above the nucleus; higher orbits have more energy. The first orbit is n=1, the second is n=2, and so on. The magnetic quantum number is just a number that represents which direction the electron is pointing. The other important quantum mechanical property, called spin, is related to the fact that electrons come in pairs. In each pair, one electron spins one way (with a spin of one half), and the other electron spins the other way (with a spin of negative one half). Two electrons with the same spin cannot exist as a pair. This might seem kind of random, but it has effects in terms of how magnetic material is. Materials that have unpaired electrons are more likely to be magnetic