Answer:
a.) 1.8 metre
b.) 66.67 Hz
Explanation: Given that the
Length L = 0.9m
Wavelength (λ) = 2L/n
Where n = number of harmonic
If n = 1, then
Wavelength (λ) = 2L = 2 × 0.9 = 1.8 m
b.)
If waves travel at a speed of 120m/s on this string, what is the frequency
associated with the longest wave (first harmonic)?
Given that V = 120 m/s
V = Fλ
But λ = 2L, therefore,
F = V/2L
F = 120/1.8
F = 66.67 Hz
Acceleration is change in velocity over time --> 
Δv or change in velocity equals the Final velocity minus the initial velocity
Our initial velocity here is 60m/s while our final velocity is 0 m/s
The time interval is 85 seconds so...
The negative is there to indicate that the train in slowing down or decelerating
The Martian acceleration of gravity (as measured by this jury-rigged device) is
(0.4 cm/1.08 cm) x (9.81 m/s²)
That's <em>3.63 m/s²</em> .
Google says 3.711 m/s², so I guess that's not too bad.
Only about 2% wrong.
You might see the word alloy described as a "mixture of metals", but that's a little bit misleading because some alloys contain only one metal and it's mixed in with other substances that are nonmetals (cast iron, for example, is an alloy made of just one metal, iron, mixed with one nonmetal, carbon). The best way to think of an alloy is as a material that's made up of at least two different chemical elements, one of which is a metal. The most important metallic component of an alloy (often representing 90 percent or more of the material) is called the main metal, the parent metal, or the base metal. The other components of an alloy (which are called alloying agents) can be either metals or nonmetals and they're present in much smaller quantities (sometimes less than 1 percent of the total). Although an alloy can sometimes be a compound (the elements it's made from are chemically bonded together), it's usually a solid solution (atoms of the elements are simply intermixed, like salt mixed with water).
