17/6 ÷ 34/72 please it is urgent
Answers
Answer:
answer is 6
Step-by-step explanation:
→17/6÷34/72
→17/6×72/34
→6
Answer :-
Position of the object is 13.33 cm from the mirror .
Explanation :-
We have :-
→ Focal length = 20 cm
→ Size of image is thrice the object .
________________________________
From the question, we have :-
• hᵢ = 3hₒ
Now, from the formula of Magnification of spherical mirror :-
m = -(v/u) = hᵢ/hₒ
⇒ -(v/u) = 3hₒ/hₒ
⇒ -(v/u) = 3
⇒ v/u = -3
⇒ v = -3u
________________________________
According to sign convention :-
• f = -20 cm
Now, let's calculate the position of the object by using the mirror formula .
1/v + 1/u = 1/f
⇒ 1/(-3u) + 1/u = 1/(-20)
⇒ -1/3u + 1/u = -1/20
⇒ (-1 + 3)/3u = -1/20
⇒ 2/3u = -1/20
⇒ 3u(-1) = 2(20)
⇒ -3u = 40
⇒ u = 40/(-3)
⇒ u = -13.33 cm
[According to sign convention, 'u' is always -ve for a concave mirror.]