Answer:
118 N
Explanation:
Given mass of the block, m = 4.00kg.
The acceleration of the elevator, a = 3.0 m/s^2.
As elevotar attaced with spring scale and accelerating upward
(block and elevator), so total force
Here, mg is the weight of the block downward direction.
or
substitute the given value, we get
= 117.6 N = 118 N.
Thus, the reading on the spring scale to 3 significant figures is 118 N.
1) Size of the image: 2 cm
In order to calculate the size of the image, we can use the following proportion:
where
p = 80 m is the distance of the tree from the pinhole
q = 20 cm = 0.2 m is the distance of the image from the pinhole
= 8 m is the heigth of the object
is the height of the image
By re-arranging the proportion, we find
2) Magnification: 0.0025
The magnification of a camera is given by the ratio between the size of the image and the size of the real object:
so, in this problem we have