Answer:
F'= 4F/9
Explanation:
Two small objects each with a net charge of +Q exert a force of magnitude F on each other. If r is the distance between them, then the force is given by :
...(1)
Now, if one of the objects with another whose net charge is + 4Q is replaced and also the distance between +Q and +4Q charges is increased 3 times as far apart as they were. New force is given by :
.....(2)
Dividing equation (1) and (2), we get :

Hence, the correct option is (d) i.e. " 4F/9"
Density is mass divided by volume. rho=m/v. So, v=m/rho. In frank's case this is 80/8 = 10 cm^3.
Density-Dependent:
1<span><span><span><span>. </span>competition.</span><span>
<span>2. </span>overcrowding.</span><span>
3<span>. </span>predators.</span></span><span>
(These are a few from a test I took, hopefully they help you a bit >.<)</span></span>
Answer : Relatively hot objects
Explanation : We know that, the temperature of the objects is inversely proportional to their wavelengths. The objects emitting radiation in the visible region have short wavelength and hence are relatively hotter.
We know the range of wavelength of the visible spectrum is from 400 nm to 780 nm.
It's a quantitative observation because it includes numerical data.