Answer:
d = 1.65 m
Explanation:
Given that,
The speed of a ball, v = 3 m/s
A ball rolls a level table that is 1.5 m above the floor.
We can find how long the ball is in free fall. We can use the second equation of kinematics as follows :

u is the initial speed in the vertical direction
So,

Now, using the formula of velocity.

So, the landing spot is at 1.65 m from the table.
No the only thing that affects it is how it is built
D is the wrong answer. New information does often completely change the theory. Its hard to change something and leave the major theory intact.
Answer:
(b) The electrons, because they have the smaller momentum and, hence, the larger de Broglie wavelength
Explanation:
de Broglie wavelength λ = h / m v
Since both electrons and protons have same velocity , momentum mv will be less for electrons because mass of electron is less .
for electron , momentum is less so . Therefore de Broglie wavelength λ will be more for electrons .
Amount of diffraction that is angle of diffraction is proportional to λ
Therefore electrons having greater de Broglie wavelength will show greater diffraction.