Answer:
Part a)

Part b)
v = 3.64 m/s
Part c)

Part d)

Explanation:
As we know that moment of inertia of hollow sphere is given as

here we know that

R = 0.200 m
now we have


now we know that total Kinetic energy is given as





Part a)
Now initial rotational kinetic energy is given as



Part b)
speed of the sphere is given as
v = 3.64 m/s
Part c)
By energy conservation of the rolling sphere we can say




Part d)
Now we know that




Work = (force) x (distance)
80 J = (force) x (4 m)
Force = (80 J) / (4 m) = 20 N
That's IF the force was in the same direction as the 4m of motion.
If the force was kind of slanted, then it had to be stronger, and
it had a component of 20N in the direction of the motion.
Answer:
a) La aceleración angular es: 
b) El engranaje gira 125 radianes.
c) El engranaje hara aproximadamente 20 revoluciones.
Explanation:
a)
La aceleración angular se define como:

Donde:
- Δω es la diferencia de velocidad angular (en otras palabras ω(final)-ω(inicial))
- Δt es el tiempo en el que occure el cambio de velocidad angular


b)
El desplazamiento angular puede ser calculado usando la siguiente ecuación:

Aqui el angulo inicial es 0, por lo tanto.


El engranaje gira 125 radianes.
c)
Lo que debemos hacer aquí es convertir radianes a revoluciones.
Recordemos que 2π rad = 1 rev
Entonces:

Por lo tanto el engranaje hara aproximadamente 20 revoluciones.
Espero te haya sido de ayuda!
When an object is acted on by an unbalanced force, then that object will accelerate.