Answer:
38.8 m
Explanation:
h = -(21 + 1.75) = - 22.75 m
g = - 9.8 m /s^2
Ux = 14.004 m/s
Uy = + 5.376 m/s
Let the ball hits the ground in time t and at a distance d from the base of hill.
Use second equation of motion
h = Uyt + 0.5 at^2
- 22.75 = 5.376 t - 0.5 x 9.8 t^2
4.9 t^2 - 5.376 t - 22.75 = 0

By solving
t = 2.77 second
So, horizontal distance
d = Ux t
d = 14.004 x 2.77 = 38.8 m
Answer:
B. +m
Explanation:
The magnification of an image is defined as the ratio between the size of the image and of the object:

where we have
y' = size of the image
y = size of the object
There are two possible situations:
- When m is positive, y' has same sign as y: this means that the image image is upright
- When m is negative, y' has opposite sign to y: this means that the image is upside down
Therefore, the correct option representing an upright image is
B. +m