4. The chart shows melting and boiling points of different substances.

Melting and Boiling Points

Substance

Alcohol

Formaldehyde

Nicotine

Benzene

Nitroglycerine

Melting Point ("C) Boiling Point ("C)

-114

78.2

-92

-19

-79

247

5.5

80

13.5

250

Which substance freezes at the lowest

temperature?

A. Alcohol

B. Nicotine

C. Formaldehyde

Consider two metallic rods mounted on insulated supports. one is neutral, the other positively charged. you bring the two rods close to each, but without contact, and briefly ground the the neutral rod by touching it with your hand. show answer correct answer what would be resulting charge (if any) on the initially neutral rod

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

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?