Answer:
A type of telescope that does not require darkness in order to be able to use it is the refracting telescope
Explanation:
A refracting telescope consists of a lens and an eyepiece collects light which is then focused to present a magnified, bright and clear image.
The incident light on a refracting telescope is bent by refraction such that the light is focused to the focal point.
In refracting telescopes, the image is formed by bending light, that is by refraction.
The refracting telescope technology has been applied to binoculars and camera zoom lenses.
Explanation:
It is given that,
Focal length of the concave mirror, f = -13.5 cm
Image distance, v = -37.5 cm (in front of mirror)
Let u is the object distance. It can be calculated using the mirror's formula as :



u = -21.09 cm
The magnification of the mirror is given by :


m = -1.77
So, the magnification produced by the mirror is (-1.77). Hence, this is the required solution.
D ............................
Answer
Any force greater 490N
Explanation
The force required just to make an object slide over a rough horizontal surface is any force greater that the static friction which given by;

Given;

Hence;
F = 0.5 x 100 x 9.8
F = 490N.
We will only need the coefficient of kinetic friction if we were asked to find the force required to keep the object moving uniformly. Usually, the force needed to keep an object moving uniformly over a rough surface is lesser that which is needed to start its motion.
In this problem, we were only asked to find the minimum force required to make the object move which we have done.
Answer:
Just to help, periods on the periodic table are those running horizontally from left to right