Convert the given in SI units.
(44 ft/sec)(1 m/ 3.28 ft) = 13.41 m/sec
The distance traveled and the initial velocity can be related through the equation,
d = (Vf)² - (Vi)²/ 2a
where d is the distance, Vf is the final velocity, Vi is the initial velocity, a is the acceleration due to gravity. Substituting the known values from the given above,
d = ((0 m/s)² - (13.41 m/s)²)/ 2(-9.8 m/s²)
The value of d from the equation,
d = 9.17 meters
Convert this to feet,
d = (9.17 m)(3.28 ft / 1 m) = 30 ft
Answer: 30 ft
Thiết bị không phải nguồn điện:
Đáp án D
An object distance is
presented as s = 5f and we know that the mirror equation relates the image
distance to the object distance and the focal length.
The mirror equation is
1/f = 1/s + 1/s’ where the variable f stands for
the focal length of the mirror. Variable (s)
represents the distance between the mirror surface and the object and the
variable <span>(s’) represents the distance between the mirror surface and
the image. </span>
In addition, a concave mirror
will have a positive focal length (f) and a convex mirror will have a negative
focal length (f).
Now, we then have 1/f = 1/5f
+ 1/s’ which is s’ = 5f/4
Then we get the magnification
ratio that expresses the size or amount of magnification or reduction of the
object or image and to get the magnification, we use this equation: M= s’/s
M= 5f/4x5f
s’ = 1/4s
Therefore, the image height
is one fourth of the object height
