Answer:
90km
Explanation:
every hour you travel 30km and you are traveling 3 hours 30×3
Answer: a. 667N
b. 665N
c. 54.5N
Explanation:
a) on the surface of the earth
W = mg
W = 68 × 9.81
= 667N
b) at the top of Everest (8848 m above sea level).
W =mg × R²/(R + H)²
W = 667 × [6378²/(6378 + 8.848)²
W = 665N
c) has 2 1/2 times the radius of the earth
W = mg × R²/(R + H)²
W = 667 × R²/(R + 2.5R)²
W = 54.5N
Answer:3.54ohms
Explanation: connection in parallel
1/Rt= 1/R1+1/R2+1/R3
1/Rt= 1/16+1/13+1/7
1/Rt= 91+112+208/1456
1/Rt= 411/1456
411Rt= 1456
Rt= 1456/411
Rt= 3.54ohms
1) Focal length
We can find the focal length of the mirror by using the mirror equation:

(1)
where
f is the focal length

is the distance of the object from the mirror

is the distance of the image from the mirror
In this case,

, while

(the distance of the image should be taken as negative, because the image is to the right (behind) of the mirror, so it is virtual). If we use these data inside (1), we find the focal length of the mirror:

from which we find

2) The mirror is convex: in fact, for the sign convention, a concave mirror has positive focal length while a convex mirror has negative focal length. In this case, the focal length is negative, so the mirror is convex.
3) The image is virtual, because it is behind the mirror and in fact we have taken its distance from the mirror as negative.
4) The radius of curvature of a mirror is twice its focal length, so for the mirror in our problem the radius of curvature is:
This is a limitation of kinetic-molecular energy. Right?