The correct answer is:
Work is negative, the environment did work on the object, and the energy of the system decreases.
In fact, the work-energy theorem states that the work done by the system is equal to its variation of kinetic energy:
In this problem, the variation of kinetic energy 
is negative (because the final velocity is less than the initial velocity), so the work is negative, and this means that the environment did work on the object, and its energy decreased.
Answer:
Grow up man, this is completely based on your curriculum, we would need your book to answer, and this has to be done by you.
Answer:
20 degrees.
Explanation:
From Snell’s law of refraction:
sinθ1•n1 = sinθ2•n2
where θ1 is the incidence angle, θ2 is the refraction angle, n1 is the refraction index of light in medium1, and n2 is the refraction index for virgin olive oil. The incidence angle of the red light is θ1 = 30 degrees.
The red light is in air as medium1, so n1 (air) = 1.00029
So, to find θ2, the refracted angle:
sinθ1•1.00029 = sinθ2•1.464
sin(30)•1.00029 / 1.464 = sinθ2
0.5•1.00029 / 1.464 = sinθ2
sinθ2 = 0.3416291
θ2 = arcsin(0.3416291)
θ2 = 19.976 degrees
To the nearest degree,
θ2 = 20 degrees.
When a force is applied to the box , this will cause an acceleration to the box.
(force =mass×acceleration)
So the box has a constant acceleration and a changing velocity.
