(a) No, because the mechanical energy is not conserved
Explanation:
The work-energy theorem states that the work done by the engine on the airplane is equal to the gain in kinetic energy of the plane:
(1)
However, this theorem is only valid if there are no non-conservative forces acting on the plane. However, in this case there is air resistance acting on the plane: this means that the work-energy theorem is no longer valid, because the mechanical energy is not conserved.
Therefore, eq. (1) can be rewritten as
which means that the work done by the engine (W) is used partially to increase the kinetic energy of the airplane () and part is lost because of the air resistance ().
(b) 77.8 m/s
First of all, we need to calculate the net force acting on the plane, which is equal to the difference between the thrust force and the air resistance:
Now we can calculate the acceleration of the plane, by using Newton's second law:
where m is the mass of the plane.
Finally, we can calculate the final speed of the plane by using the equation:
where
is the final velocity
is the initial velocity
is the acceleration
is the distance travelled
Solving for v, we find
Answer:
Newtons law
Explanation:
According to this law, a body at rest tends to stay at rest, and a body in motion tends to stay in motion, unless acted on by a net external force.
Nuclear fusion because atomic nuclei combine to form a heavier nucleus. Option A is correct.
<h3>What is nuclear fusion?</h3>
The process by which two or more tiny nuclei unite to generate a bigger nucleus is known as a nuclear fusion reaction.
The more energy it takes to liberate an electron from a smaller atom. This is referred to as binding energy.
As a result, when two little nuclei fuse together, there is more binding energy than when two big nuclei fuse together.
For example, the fusion of two hydrogen atoms produces more energy than the fusion of one helium atom, and surplus energy is expelled into space upon binding.
Nuclear fusion because atomic nuclei combine to form a heavier nucleus.
Hence, option A is correct.
To learn more about nuclear fusion refer to the link;
brainly.com/question/14019172
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Answer:
Precisely, water has to absorb 4,184 Joules of heat (1 calorie) for the temperature of one kilogram of water to increase 1°C. For comparison sake, it only takes 385 Joules of heat to raise 1 kilogram of copper 1°C.
Explanation: