Explanation:
It is given that,
Distance, r = 3.5 m
Electric field due to an infinite wall of charges, E = 125 N/C
We need to find the electric field 1.5 meters from the wall, r' = 1.5 m. Let it is equal to E'. For an infinite wall of charge the electric field is given by :

It is clear that the electric field is inversely proportional to the distance. So,


E' = 291.67 N/C
So, the magnitude of the electric field 1.5 meters from the wall is 291.67 N/C. Hence, this is the required solution.
Answer:
The probability of higher energy state is 0.4200.
Explanation:
Given that,
Temperature = 247 K
Energy difference between two states 
We need to calculate the probability of higher energy state
Probability of 
Probability of 
The total probability is

Here, E₁ = lower energy state
E₂ = higher energy state
Put the value of E₁ in to the formula



Here, 
Put the value into the formula


Hence, The probability of higher energy state is 0.4200.
Efficiency of a simple machine is the ratio of mechanical advantage and speed ratio.
If mechanical advantage = speed ratio then efficiency = 1
Which is impossible for a practical machine due to presence of frictional force which wastes some energy and thus lowers the output
Answer:
nebulas and they are the cool clouds in which stars form
Explanation:
The stars are born by chance. Fragments of matter are gathered from the cool clouds of gas and dust that float in space, the so-called nebulas. These particles are added by gravitational attraction to form a large mass.
This conglomerate, due to the effect of gravity, contracts on itself and as a consequence increases in its center, density, pressure and heat. In this way, atoms move faster and collide with each other. Under these conditions, nuclear fusion reactions soon begin. When they start the star is born.
Answer:
In helium
Explanation:
Since the units are the same, the value should only be considered.