Part 1) Through what potential difference would an electron have to be accelerated from rest to give it a de Broglie wavelength of 1.2 × 10^ −10 m?

The mass of an electron is 9.109 × 10^ −31 kg and Planck's constant is 6.626 × 10 ^−34 J s

Answer in Volts.

Part 2) A ball has a mass of 0.303 kg just before it strikes the Earth after being dropped from a

building 78.7 m tall. The acceleration of gravity is 9.8 m/s ^2 .

What is its de Broglie wavelength?

Answer in units of m.