Answer:
a) Due to the characteristic that a converging lens focuses light rays from infinity and parallel to its main axis. Therefore, the lens should be placed at a distance "f" from the film, in this way it will form the image of the object placed at infinity in said film.
b) Since the converging lens produces an image of an object placed at a distance of 2f, the lens must be placed at the same distance (2f), so that this object that is placed at a distance of 2f is focused.
Explanation:
We can solve the problem by applying Newton's second law, which states that the resultant of the forces acting on an object is equal to the product between its mass and its acceleration:

We should consider two different directions: the direction perpendicular to the inclined plane and the direction parallel to it. Let's write the equations of the forces along the two directions, decomposing the weight of the object (mg):

(parallel direction) (1)

(perpendicular direction) (2)
where

is the angle of the inclined plane, N is the normal reaction of the plane,

is the frictional force, with

being the coefficient of friction.
From eq.(2), we find

and if we substitute into eq.(1), we can find the acceleration of the block:

from which
Answer:
3.2 m/s²
Explanation:
Acceleration can be calculated as:
v = u + at (where v is final velocity, u is initial velocity, a is acceleration and t is time)
25 m/s = 9 m/s + a(5 s) (a is unknown)
16 m/s = a(5 s)
a = 3.2 m/s²
We assume that this is a uniform acceleration (meaning that the velocity increases at an equal rate for those 5 seconds).
Answer:
because gravity pulled us in the land if there is no gravitational force there will not be field force too
Explanation:
hope it's will help you