13. The period of a wave is 10 seconds and its wavelength is 2 meters. What is the wave's speed?
Before trying to solve for wave speed, there are questions you must answer. Answer the questions below based
on the problem 13. These questions will lead you to answering the problem.
A. Out of the two things you mentioned, which one is given in the problem?
c. Did you notice that you were not given frequency? But you know the period, so you
f
Period
can solve for frequency. Solve for frequency. Use the equation on the right.
d. Now that you know the frequency, using the frequency and wavelength, solve for the wave speed. Use
GUESS
Unknown
Equation
Substitute
Solve
f=
12 m/h
Given

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid

no

sodium is solid at rt

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.