Please answer all you can For the following 3 questions, use the formula to solve for the unknown values:
v=f∙(2L)/n, where n is an integer that represents the number of half-wavelengths.

1. The speed of a wave in a particular string is 480 m/s. Determine the frequency that will create a half-wavelength standing wave (n=1) if the length of the string is 0.8 m.

2. Determine the length of string required to produce a full wavelength standing wave (n=2) with a frequency of 250 Hz. The speed of waves in this string is 400 m/s.

3. A string with a length of 0.7 m is plucked. The speed of a wave in the string is 350 m/s. Calculate the frequency needed to create the first 3 standing waves in this string.

Air is held within a frictionless piston-cylinder container, which is oriented vertically. the mass of the piston is 0.45 kg and the cross-sectional area is 0.0030 m2. initially (state 1) the pressure of the gas is sufficient to support the weight of the piston as well as the force exerted by the atmospheric pressure ( 101.32 kpa). the volume occupied by the air within the cylinder in state 1 is 1.00 liter. one end of a spring (with spring constant k = 1000 n/m) is attached to the top of the piston, while the other end of the spring is attached to a stage that can move vertically. initially the spring is undeflected and therefore exerts no force. then the stage is then moved quasistatically downward a distance of 10.0 cm, at which point the system reaches state 2. the piston-cylinder is not insulated; rather it remains in diathermal contact with the surroundings, which are at a constant temperature of 300 k. what is the change of pressure within the container?

When an object is heated it contracts. a. true b. false

Which is the most accurate name for the ionic compound cas?