Integrated Concepts The practical limit to an electric field in air is about 3.00 6? × 10? N/C. Above this strength, sparking takes place because air begins to ionize and charges flow, reducing the field. (a) Calculate the distance a free proton must travel in this field to reach 3.00% of the speed of light, starting from rest. (b) Is this practical in air, or must it occur in a vacuum?

Solution : In the above question they have given the limit to an electric field in air is about 3.00 × 10 N/C. Step 1 (a) Calculate the distance a free proton must travel in this field to reach 3.00% of the speed of light, starting from rest First we need to calculate the distance of a free proton must travel in this field to reach 3.00% of the speed of light, So we need to calculate the coulomb’s law of electrostatic field is,’ F = qE Here q s charge of proton, E is the electric field. Next we need to calculate from Newton’s second law F = ma Here, m is the mass of proton and a is the acceleration of proton.