The total work <em>W</em> done by the spring on the object as it pushes the object from 6 cm from equilibrium to 1.9 cm from equilibrium is
<em>W</em> = 1/2 (19.3 N/m) ((0.060 m)² - (0.019 m)²) ≈ 0.031 J
That is,
• the spring would perform 1/2 (19.3 N/m) (0.060 m)² ≈ 0.035 J by pushing the object from the 6 cm position to the equilibrium point
• the spring would perform 1/2 (19.3 N/m) (0.019 m)² ≈ 0.0035 J by pushing the object from the 1.9 cm position to equilbrium
so the work done in pushing the object from the 6 cm position to the 1.9 cm position is the difference between these.
By the work-energy theorem,
<em>W</em> = ∆<em>K</em> = <em>K</em>
where <em>K</em> is the kinetic energy of the object at the 1.9 cm position. Initial kinetic energy is zero because the object starts at rest. So
<em>W</em> = 1/2 <em>mv</em> ²
where <em>m</em> is the mass of the object and <em>v</em> is the speed you want to find. Solving for <em>v</em>, you get
<em>v</em> = √(2<em>W</em>/<em>m</em>) ≈ 0.46 m/s
Current = (voltage) / (resistance)
= (1.5 V) / (0.35 ohms)
= 4.28 Amperes.
==> The battery will not last long.
==> The ammeter is broken ... it's reading less than 0.25 Amps.
Anything that happens once every half-second can do it twice in 1 second.
So the frequency is 2 per second. (<em>2 Hz</em>)
Answer: Taking into account sound is a wave, we can use the information of the displacement (generally given as a graph) to find the wavelength and frequency, then we can calculate the speed with the formula of the speed of a wave.
Explanation:
If we have the displacement graph of the sound wave, we can find its amplitude, its wavelength and period (which is the inverse of frequency).
Now, if we additionally have the frequency as data, we can use the equation of the speed of a wave:
Where:
is the speed of the sound wave
is the wavelength
is the frequency