If you write down the formula for friction, you will get an answer.
Ff = u * N Where N is a push down force that an object experiences.
u (mu) is a constant and has no units
It may not be accelerating and still experience friction. A is not correct.
Color and Density will not affect the frictional force. B is not so.
Buoyant forces are a different thing altogether. Generally friction has nothing to do with them. C is incorrect.
The last one is your answer. Technically mg should be the answer and not mass, but the second part is correct.
Explanation:
A micrometer is a measuring device or an instrument which is used to measure very minute measurements very accurately and precisely. It is mathematical tool used to provide accurate measurement for any mechanical components.
Now, if the micrometer that I have found is badly bent, it would provide faulty or wrong measurements both in terms of precision and accuracy when compared to a high quality meter stick.
Answer:
Equilibrium. • When an object is in equilibrium (either at rest or moving with constant velocity), the net force acting on it zero.
Because they have wings that can nake them fly
Answer:
24.71 mm
Explanation:
Distance is proportional to focal length, so
d∝f
which means

Magnification of first lens

and

Similarly, magnification of second lens

and

From the above equations we get

and

which means,

and

So, we get

∴ Focal length should this camera's lens is 24.71 mm