Question
An object moves towards a convex lens of focal length 20
cm with a velocity of 5 cm/s. When the object is at 30 cm from the lens, find the rate at which the image is moving.Solution
Given:
- Focal length of convex lens, f = +20 cm
- Object distance at a given instant, u = –30 cm (object is in front ⇒ negative in sign convention)
- Object velocity: du/dt = +5 cm/s (since it's moving towards the lens, u is decreasing ⇒ du/dt is positive)
dv/dt = ?, i.e., rate of change of image position. Using lens formula: 1/v – 1/u = 1/f Differentiate both sides with respect to time t :
The image is moving away from the lens at a rate of 20 cm/s.
More Physics GS Questions
Which database level is closest to the users?
Efficiency of the token ring is high if-
In a 5-stage pipeline (Fetch, Decode, Execute, Memory, Write-back), how many instructions can be in various stages of processing at the same time?
In a 2-to-1 multiplexer, how many select lines are required to choose between two data inputs?
- The logic operations of two combinational circuits in Figure-I and Figure-II are
What is the primary purpose of data deduplication in storage management?
What is the primary advantage of using a snapshot-based backup method over traditional backup methods?
What is the primary goal of requirement analysis in software development?
PGP is abbreviated as _______________
The CPU control unit typically generates control signals for various components within the CPU, including the:
Relevant for Exams:
