For a huge luxury liner to move with constant velocity, its engines need to supply a forward thrust of 7.80 105 N. What is the magnitude of the resistive force exerted by the water on the cruise ship

Explanation:

Given data

To find

Magnitude of the resistive force

Solution

As from Newtons second law:

When velocity is constant then  acceleration a=0

So the magnitude of resistive force exerted by the water on the cruise ship

is equal to the magnitude of forward thrust but the directions of forces are opposite(according to Newtons third law)

So

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000