The speed of a proton after it accelerates from rest through a potential difference of 350 V is
.
Initial velocity of the proton 
Given potential difference 
let's assume that the speed of the proton is
,
Since the proton is accelerating through a potential difference, proton's potential energy will change with time. The potential energy of a particle of charge
when accelerated with a potential difference
is,

Due to Work-Energy Theorem and Conservation of Energy - <em>If there is no non-conservative force acting on a particle then loss in Potential energy P.E must be equal to gain in Kinetic Energy K.E</em> i.e

If the initial and final velocity of the proton is
and
respectively then,
change in Kinetic Energy 
change in Potential Energy 
from conservation of energy,

so, 

To read more about the conservation of energy, please go to brainly.com/question/14668053
Answer:
See explanation
Explanation:
Given that the density of the unknown substance is 0.79 g/cm3 and is soluble in water, the possible substances it could be are;
i) t-butanol
ii) ethanol
iii) 2-propanol
iv) acetone
However, the actual identity of the unknown substance can be obtained by carrying out a boiling point test. The four substances listed above have different boiling points. Hence the boiling point of the unknown substance ultimately discloses its identity.
The role lightning plays in earth is when the earth is charged with positive protons, the lightning is the electron.
This question involves the concepts of th magnetic field and current.
The magnetic field created by the current at the house is "6.75 x 10⁻⁷ T".
<h3>Magnetic Field</h3>
The magnetic field created by a current carrying wire can be given by the following formula:

where,
- B = magnetic field = ?
= permeabiliy of free space =4π x 10⁻⁷- I = current = 152 A
- r = distance = 45 m

B = 6.75 x 10⁻⁷ T
Learn more about magnetic field here:
brainly.com/question/23096032
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