Answer:
Lens and the virtual image was the image distance. Error was made when measuring the distances and determining values that were reasonable for focal length, so this error was accounted for when calculating the focal length by adding or subtracting uncertainties from the values.Plane mirrors, convex mirrors, and diverging lenses can never produce a real image. A concave mirror and a converging lens will only produce a real image if the object is located beyond the focal point (i.e., more than one focal length away). 5.
Answer:

Explanation:
Given:
sides of the cube, 
speed of the cube with respect to the observer, 
Since the relative velocity of the object is relativistic, so there will be a length contraction according to the observer:
where:
observed length of the side along the direction of velocity

is the observed length of the cube edge only in the direction of the velocity due to relativistic effect of length contraction.
So the observed volume will be:



Answer:
When glass rod is rubbed with silk clothes, glass quickly loses electrons, and silk takes electrons out of the glass rod