El trabajo hecho por la gravedad durante el descenso de un proyectil es:

a) positivo.

b) negativo.

c) cero.

d) depende de la dirección del eje y.

e) depende de la dirección del eje x.

Explanation:

The question is

The work done by gravity during a projectile decline is:

a) Positive.

b) Negative.

c) Zero.

d) Depends on y-axis direction.

e) Depends on x-axis direciton.

Remember that Work is defined as the energy needed to move an object. Mathematically, it's the product between the force exerted and the displacement. That means if we don't have any displacement, then there's no work.

In this case, we are talking about the work done by the gravity force. When a projectile goes down, it's because of the gravity force, which means it can't be zero.

Specifically, the work done by gravity is positive, because when the projectile is going down, it's getting closer to the atracttive mass, which is Earth.

Therefore, the right answer is a.

explanation:

v=uf/(u-f)

= 5.-10/(5+10) convex lens has negative focal length

c. magnitude and direction