Answer:
80mm or 8cm
Explanation:
According to the lens formula,
1/f = 1/u+1/v
If the object distance u = 4cm = 40mm
Object height = 1.5mm
Image height = 3mm
First, we need to get the image distance (v) using the magnification formula Magnification = image distance/object distance = Image height/object height
v/40=3/1.5
1.5v = 120
v = 120/1.5
v = 80mm
The image distance is 80mm
To get the focal length, we will substitute the image distance and the object distance in the mirror formula to have;
1/f = 1/40+1/-80
Note that the image formed by the lens is an upright image (virtual), therefore the image distance will be negative.
Also the focal length of the converging lens is positive. Our formula will become;
1/f = 1/40-1/80
1/f = 2-1/80
1/f = 1/80
f = 80mm
The focal length of the lens 80mm or 8cm
Newton's principle
newton's 2nd law of motion where F=ma
Answer:
Correct option : (c) period.
Explanation:
The time that is required for a vibrating object to complete one full cycle is called the time period. If f is the frequency of a wave, then the relation between the frequency and the time period is given by :
These are the characteristics of a wave. Some other characteristics are wavelength, amplitude, intensity etc. So, the correct option is (c) "period".
Sugar dissolves faster in hot water because, the higher the temperature the faster the molecules move.
