D = vo t - at²/2
v = vo - at
40 m = vo · 7.10 - a · ( 7.10 )²/2
40 m = 7.10 vo - a· 50.41/2
40 m = 7.10 vo - 25.205 a
2.75 m/s = vo - 7.10 a ⇒ a = ( vo - 2.75 )/ 7.10
40 = 7.10 vo - 25.205 · ( vo - 2.75 ) / 7.10
40 = 7.1 vo - 3.55 vo + 9.7625
3.55 vo = 30.2375
vo = 30.2375 : 3.55 = 8.5176 m/s
Answer: the truck`s original speed is 8.5176 m/s.
Answer:
The frequency does not depend on the amplitude for any (ideal) mechanical or electromagnetic waves.
In electromagnetism we have that the relation is:
Velocity = wavelenght*frequency.
So the amplitude of the wave does not have any effect here.
For a mechanical system like an harmonic oscillator (that can be used to describe almost any oscillating system), we have that the frequency is:
f = (1/2*pi)*√(k/m)
Where m is the mass and k is the constant of the spring, again, you can see that the frequency only depends on the physical properties of the system, and no in how much you displace it from the equilibrium position.
This happens because as more you displace the mass from the equilibrium position, more will be the force acting on the mass, so while the "path" that the mass has to travel is bigger, the mas moves faster, so the frequency remains unaffected.
