If coherant light is passed through two slits of the right size and separation then light and dark bands are seen on a screen at the correct distance fron the slits. This demonstrates the wave nature...
It creates an effect known as diffraction, whereby the light waves (or, if you think about it in terms of particles, as light and all other objects for that matter can be thought of as both a wave...
One inaccuracy can be that the wire or material that you are using to find Young's Modulus has some impurities and there may be a slight variation in the cross sectional area so a shorter piece of...