Answer:
30 cm
Explanation:
To solve this problem, we use the lens equation:

where
f is the focal length of the lens
p is the distance of the object from the lens
q is the distance of the image from the lens
In this problem, we know that
q = -30 cm is the distance of the image from the lens; it is negative because the image is formed in front of the lens, so it is a virtual image
We also know that the size of the image is twice that of the object, so the magnification is 2:

where M is the magnification of the lens. Solving this equation for p,

So, the distance of the object from the lens is 15 cm.
Now we can finally solve the lens equation to find f, the focal length:

Explanation:
The natural environment or natural world encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to the Earth or some parts of Earth
The answer should be ''Decrease'' to fill in the blank because squirrels usually live in trees and get food from there so without a place to live when its raining and no food to survive, than they would die and lessen their population so that's why decrease is the answer.
Answer:
R=4Ω
Explanation:
R1 and R3 are parrallel
so we have : R=R1*R2/R1+R2
R=6*3/6+3
R=18/9
R=2Ω
R2 and 2Ω are in series,so we have
R=R2+2
R=2+2
R=4Ω
Answer:
9 hours
Explanation:
For each battery:
Current = 1 A
Voltage = 1.5 V
current and EMF required = 5.0 A and 4.5 V
Since each battery has a current of 1 A, we'll need to link five of them in parallel with our load to get a current of 5 A. so that the total current equals 5 amps
. Now that each battery has a 1.5 V voltage drop and we require an emf of 4.5 V, we would use three batteries in series rather than a single battery. So, there is a need to must substitute every single battery with three batteries in series for all five single batteries linked in parallel.
So, the total no. of batteries is
= 5 × 3 = 15 batteries.
On each battery, the charge is = 3 amp hours
∴
The total charge = 15 × 3 = 45 amp hours.
Since the charge transferred within 1 hour = 5 amp
Then, the required lifetime of the battery is:
= 45 amp-hours/ 5 amp
= 9 hours