Question

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

Answer 1

Answer:

$F_{resistive}=7.80*10^{5}N$

Explanation:

Given data

$Force_{thrust}=7.80*10^{5}N$

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

$F_{resistive}-F_{thrust}=ma\\F_{resistive}-F_{thrust}=0\\Hence\\F_{resistive}=F_{thrust}\\F_{resistive}=7.80*10^{5}N$