Question

An electron moving with a velocity of 5x 10 4 m/s enters into a uniform electric
field and acquires a uniform acceleration of 10 4 m/s 2 in the direction of its initial
motion.Calculate the time in which the electron would acquire a velocity double
of its initial velocity

Answer 1

☆Concept:

Electic charge will experience force in the presence of electric field.

• positively charged particles(protons) experience forces in the direction of electric field.
• negatively charged particles(electrons) experience forces opposite to the direction of electric field.

☆Solution:

Given:

• initial velocity(u) = 5×10⁴ m/s
• final velocity (v) = 2u = 10×10⁴ m/s
• acceleration (a) = 10⁴ m/s²

By using of motion:

v = u + at

• 10×10⁴ = 5×10⁴ + (10⁴)t

• 10 × 10⁴ = 10⁴(5 + t)

• 10 = 5 + t

• t = 10 - 5 = 5s

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