Respuesta :
Answer:
12777.86N
Explanation:
This problem is approached by understanding that the impulse felt by the physics teacher is equal to his change in momentum. This is mathematically represented as follows;
[tex]Ft=mv-(-mu)................(1)[/tex]
where m is his mass, v is his final velocity, u is his initial velocity, t is the time for which the force F acts on him.
It should also be noted that while he rebounds there is a change in his direction and that is why the mu carries a negative sign.
Equation (1) can therefore be written as,
[tex]Ft=mv+mu\\F=\frac{m(v+u)}{t}.............(2)[/tex]
equation (2) is a statement of Newton's second law of motion.
Given;
m = 80.4kg
u = 4.9m/s
v = 4.0m/s
t = 56 milliseconds = 0.056s
Therefore;
[tex]F=\frac{80.4(4.9+4.0)}{0.056}\\F=\frac{80.4*8.9}{0.056}\\F=12777.86N[/tex]
