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Answer: 
The chromium nucleus will complete the reaction.
Explanation:
The given reaction is a type of radioactive nuclei decay:
Positron emission: It is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. This is also known as
-decay. In this the mass number remains same.

Now according to the given reaction:

The chromium nucleus will complete the reaction.
(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 However, in this case there is air resistance acting on the plane: this means that the work-energy theorem is no longer valid, because the mechanical energy is not conserved.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:
The force required to push to stop the car is 288.67 N
Explanation:
Given that
Mass of the car, m = 1000 kg
Initial speed of the car, u = 1 m/s
The car and push on the hood at an angle of 30° below horizontal, 
Distance, d = 2 m
Let F is the force must you push to stop the car.
According work energy theorem theorem, the work done is equal to the change in kinetic energy as :



The force required to push to stop the car is 288.67 N
Explanation:
m = mass of burrito thrown by the student = 0.5 kg
a = acceleration of the burrito thrown by the student = 3 m/s²
F = force applied by the student on the burrito = ?
According to newton's second law , the net force on an object is the product of its mass and acceleration. it is given as
F = ma
inserting the values
F = (0.5) (3)
F = 1.5 N
hence the net force on the burrito comes out to be 1.5 N