The work done on the box by the applied force is zero.
The work done by the force of gravity is 75.95 J
The work done on the box by the normal force is 75.95 J.
<h3>The given parameters:</h3>
- Mass of the box, m = 3.1 kg
- Distance moved by the box, d = 2.5 m
- Coefficient of friction, = 0.35
- Inclination of the force, θ = 30⁰
<h3>What is work - done?</h3>
- Work is said to be done when the applied force moves an object to a certain distance
The work done on the box by the applied force is calculated as;

where;
a is the acceleration of the box
The acceleration of the box is zero since the box moved at a constant speed.

The work done by the force of gravity is calculated as follows;

The work done on the box by the normal force is calculated as follows;

Learn more about work done here: brainly.com/question/8119756
Answer:
option (D) is correct.
Explanation:
According to the work energy theorem, the work done by all forces is equal to the change in kinetic energy of the body.
the kinetic energy of a body is directly proportional to the square of the speed of the body.
As the kinetic energy change, the speed of the body also change.
Option (D) is correct.
<span>NO.
Air resistance does not affect the motion of a falling object differently when the mass is greater because the mass of an object does not in any way affect the speed of falling due to gravity, and air resistance depends only on the speed of the object and its surface area.</span>
Let the rescue boat starts at an angle theta with the North
now its velocity towards East is given as


now in some time "t" it will catch the boy
so we will have

also we have

now we have



by solving above we got
