Compression and rarefraction, the other guy's answer it's wrong
The motorized toy boat experiences a net force of 0 N between 4 s and 8 s.
The motorized toy boat moves at 8 m/s (u) at 4 s and at 8 m/s (v) at 8 s. We can calculate the acceleration (a) in that period using the following kinematic expression.

The object with a mass (m) of 2.0 kg experiences an acceleration of 0 m/s². We can calculate the net force (F) in that period using Newton's second law of motion.

The motorized toy boat experiences a net force of 0 N between 4 s and 8 s.
Learn more: brainly.com/question/13447525
1790 = electrical energy / 2940 seconds
Electrical energy = 5262.6kJ
or
1.79kW X 49/60
= 1.46kWh
Share electrons, have electrical conductivity and have thermal conductivity