An element is composed of millions of atoms and a compound is composed of molecules. When an atom reacts with another atom, a molecule is formed.
For example, if sodium reacts with chloride, it forms sodium chloride (Common salt). Here, sodium and chloride are elements and sodium chloride is a molecule. In this way, millions of atoms of sodium reacts with chloride and forms common salt.
Again, when the common salt is mixed with other compounds such as water, it forms a mixture.
Answer:
T = 850 N
Explanation:
given,
mass of billboard worker = 800 N
length of scaffold = 4 m
weight of the scaffold = 500 N
worker is standing at 1 m from one end.
Tension in the rope = ?
To calculate the tension in the string we have to balance the clockwise and counterclockwise moment of the system.
Weight of the worker and the weight of the scaffold will be in clockwise direction where as the tension will be in counterclockwise direction
now,
800 x 3 + 500 x 2 = T x 4
4T = 3400
T = 850 N
hence, tension in the rope is equal to 850 N
Answer:

Explanation:
The kinetic energy possessed by particles will be

where,
M is the mass of the particle (7920938.3 MeV/c²)
c is the speed of the light
Also,
energy of the proton particle = 
where,
v is the velocity
m_p is the mass of the proton (938.3 MeV/c²)
since the energy is equal
thus,

or
![1-\frac{v^2}{c^2}=[\frac{2m_p}{M}]^2](https://tex.z-dn.net/?f=1-%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D%3D%5B%5Cfrac%7B2m_p%7D%7BM%7D%5D%5E2)
substituting the values in the above equation, we get
![1-\frac{v^2}{c^2}=[\frac{2\times 938.3 }{7920}]^2](https://tex.z-dn.net/?f=1-%5Cfrac%7Bv%5E2%7D%7Bc%5E2%7D%3D%5B%5Cfrac%7B2%5Ctimes%20938.3%20%7D%7B7920%7D%5D%5E2)
or

Hence,<u> the speed necessary for the specified condition to occur is </u><u>0.9714 times the speed of the light</u>