1- Calculate the de Broglie wavelength of an electron that travels with 5.0 x 105 m/s. Also, calculate the de Broglie wavelength of a ball with a mass of 50 g traveling with 50 Km/h. Explain why we don\'t observe wave-particle duality in our macroscopic world using the results.

2- calculate the velocity of the ball when you want the ball to have a wavelength of 10 pm. explain the validity of your answer.