If the second harmonic of a certain string is 42 Hz, what is the fundamental frequency of the string?

21 Hz

42 Hz

84 Hz

126 Hz

What are simple machines?

A sound wave travels at 330 m/sec and has a wavelenght of 2meters. calcuate the frequency and period

What type of rays are used to locate cavities in teeth? Radio waves, infrared rays, ultraviolet rays, microwaves, x-rays, or gamma rays

Why can't you you use a pump to lift water to the third floor?

What kind of charged particle was transferred between the rod and the sphere?

Tom stops using a new skin cream for five days to determine if the cream is the cause of a recent rash. What stage of the scientific method is Tom using?

Use your observations to determine qualitatively how the strength of the electric interaction between charged objects depends on the distance between them. Explain your reasoning (this is trickier than it might seem at first).

Far from any other masses, two masses, m1 and m2, are interacting gravitationally. The value for the mass of m1 suddenly doubles. What happens to the value of the gravitational force that mass m2 exerts on mass m1?

Which of the outer planets are most like Earth? How?

The pressure inside a champagne bottle can be quite high and can launch a cork explosively. Suppose you open a bottle at sea level. The absolute pressure inside a champagne bottle is 6 times atmospheric pressure; the cork has a mass of 7.