Agraduated cylinder has a mass of 50g when empty. when 30 ml of water is added, the graduated cylinder has a mass of 120g. if a rock is added to the graduated cylinder, the water level rises to 75ml and the total mass is now 250g. what is the density of the rock?

Unpolarized light falls on two polarizer sheets whose transmission axes are at right angles. a third polarizer is placed between the first two so that its axis makes a 52-degree angle with the axis of the first polarizer. a) what fraction of the incident light intensity is transmitted through the first polaroid? b) what fraction of the incident light intensity is transmitted through the second polaroid? c) what is the angle of polarization of the light that enters the third polaroid? d) what fraction of the incident light intensity is transmitted through the third polaroid. e) what happens if the middle polaroid is removed?

In an experiment, how can i change human errors? be specific.

How to calculate voltage drop in a series circuit