<h3><u>A</u><u>n</u><u>s</u><u>w</u><u>e</u><u>r</u><u>:</u><u>-</u></h3>
- Energy Transferre=11KJ
- Efficiency=35%
<h3>☆Usefully transferred energy:-</h3>






Answer:
Part A: What is the duck's speed? v=0.2m/s
Part B: How far apart are the crests behind the duck = 1m
Explanation:
The concept applied here is the DOPPLER EFFECT, for example, if one is driving towards a station at 120km/hr, a higher frequency will be heard. and if you are driving away from the station at the same speed, one will hear a much more lower frequency. Tthese effect was proposed by the Austrian physicist by name Johann Christian doppler.
The detailed steps and appropriate formula is as shown in the attached file.
Answer:
A : A restoring force acts on an object in simple harmonic motion that is directed in the same direction as the object's displacement.
Explanation:
Statement A is the false one:
A : A restoring force acts on an object in simple harmonic motion that is directed in the same direction as the object's displacement. --> FALSE. The restoring force in the simple harmonic motion is given by

where
k is the spring constant
x is the displacement of the system, measured with respect to the equilibrium position
As we can notice from the equation, there is a negative sign in front of (kx): this means that the force, F, and the displacement, x, have opposite directions. In fact, the restoring force of a simple harmonic oscillator always acts to restore the equilibrium position, therefore it acts in the opposite direction as that of the displacement.
1) Magnetic field
2) Electric current
3) Force