Electrons Are Accelerated to a Speed of 4

Multiple Choice

Electrons are accelerated to a speed of 4.0 × 10⁴ m/s and are aimed at a double-slit apparatus.Interference fringes are detected.If the electrons were replaced by neutrons,what speed must neutrons have to produce interference fringes with the same fringe spacing as that observed with the electrons?

A) 2.2 × 10¹ m/s
B) 7.3 × 10⁷ m/s
C) 1.7 × 10⁶ m/s
D) 9.3 × 10² m/s