Surface currents are caused by winds. They move warm water away from the equator and cool water away from the poles.
Hope it help
Radar waves are the waves with the lowest energy.
The cart comes to rest from 1.3 m/s in a matter of 0.30 s, so it undergoes an acceleration <em>a</em> of
<em>a</em> = (0 - 1.3 m/s) / (0.30 s)
<em>a</em> ≈ -4.33 m/s²
This acceleration is applied by a force of -65 N, i.e. a force of 65 N that opposes the cart's motion downhill. So the cart has a mass <em>m</em> such that
-65 N = <em>m</em> (-4.33 m/s²)
<em>m</em> = 15 kg
