Answer:
A) some of the rocks energy is transformed to thermal energy
Explanation:
If we neglect air resistance during the fall of the rock, than the mechanical energy of the rock (which is sum of its potential energy and its kinetic energy) would be constant during the entire motion, so the total energy of the rock at the top would be the same as the sum of its potential energy and kinetic energy at the bottom.
However, this not occurs, due to the presence of air resistance. In fact, air resistance acts against the fall of the rock, and because of the friction between the molecules of air and the surface of the rock, the rock loses part of its energy. This energy is converted into thermal energy of the molecules of the air.
No work is done because the object needs to be moved. The formula for work is Work = Force x Distance.
Answer:
- Amplitude = 5 cm (Heights)
- Wavelength (λ) = 40 cm
-
Wave speed (v) = 12 m/s (Approx)
- Time period (T) = 0.033 s (Approx)
- Maximum particle speed (V) = 9.43 m/s
Explanation:
1) Amplitude
Amplitude = 5 cm (Heights)
2) Wavelength (λ)
Wavelength (λ) = 40 cm
3) Wave speed
Wave speed (v) = √ t / μ
Wave speed (v) = √ 3.6 / [25x10⁻³]
Wave speed (v) = 12 m/s (Approx)
4) Time period (T)
Time period (T) = 1/f = (λ)/v
Time period (T) = 0.40m / 12
Time period (T) = 0.033 s (Approx)
5) Maximum particle speed (V)
Maximum particle speed (V) = Aw
Maximum particle speed (V) = [0.05x2x3.14] / 0.033
Maximum particle speed (V) = 9.43 m/s