The force needed to overcome sliding friction is more than the force needed to overcome rolling friction or static or even fluid
the difference between a resultant and equilibrant vector is that resultant vector is a direct quantity, one with both magnitude and direction, while the equilibrant vector is a force equal to, but opposite of, the resultant sum of vector forces, that force which balances other forces.
Alright, to begin with. The unit of Force is in Newtons. Meaning the first two options are out of the answers. Now in order to find the force. You will need to take the mass and multiply that by the acceleration. Which will give you 26.75 Newtons.
Wave speed = (wavelength) x (frequency)
Wave speed = (3 m) x (15 Hz)
<em>Wave speed = 45 m/s</em>