Answer:
B. QC > 0; QH < 0
Explanation:
Given that there are two reservoir of energy.
Sign convention for heat and work :
1.If the heat is adding to the system then it is taken as positive and if heat is going out from the system then it is taken as negative.
2. If the work is done on the system then it is taken as negative and if the work is done by the system then it is taken as positive.
From hot reservoir heat is going out that is why it is taken as negative

From cold reservoir heat is coming inside the reservoir that is why it is taken as positive

That is why the answer will be
,
Answer:
Part a)

Part b)


Part c)


Explanation:
Part a)
frequency of light will not change with change in medium but it will depend on the source only
so here frequency of light will remain same in both water and glass and it will be same as that in air



Part b)
As we know that the refractive index of water is given as

so the wavelength in the water medium is given as



Similarly the refractive index of glass is given as

so the wavelength in the glass medium is given as



Part c)
Speed of the wave in water is given as



Speed of the wave in glass is given as



Answer:
c it is not accelerating on it's on but gravity pulls it there for velocity increases.
It would be B. since the scanning shows what the terrain is down there
(I listened)
Answer: 20cm
Explanation:
Given the following data:
Magnification of image = - 1.50
Distance of image from the lens = 30.0cm
The Magnification of an image is the ratio of the image distance from the lens and the object distance from the lens.
Mathematically,
Magnification(M) = - (image distance (di) / object distance (do))
M = - (di/do)
-1.50 = - (30/do)
do = 30 / 1.5
do = 20 cm
Object is placed at a distance of 20cm from the lens.