The complete question is :
Charlie is investigating friction. She will use the same amount of force to push two wooden balls across two level surfaces. Then she will record her results in the table below.
Which prediction will most likely describe how friction will affect her findings?
Answer:
The distance for Trial 3 will be greater than the distance for Trial 4 because the difference in surface roughness will affect friction.
Explanation:
The frictional force depends greatly on the roughness of the body surfaces. It acts opposite to the direction of motion when two body surfaces have a relative motion between them.
In the context, equal mount of force is applied to push the wooden balls. So the net force which acts on the balls are :
F' = F - f
Here, F = the force applied
f = force of friction
And f = μ.N (N = reaction force)
Here μ is the coefficient of friction that depends on the surface roughness. The frictional force will be less when the surfaces are smooth. Thus for the trails 3 and trial 4, the distance for trail 3 would be greater than trail 4 as the surface is polished and would offer less friction.
Answer:
C. The ratio would not show any changes in the following year.
Explanation:
Since the introduced (and only) predator can not differentiate between the tone of the lizards (dark and light), you can assume it will feed from them in an equal proportion, so the ratio between dark green and light green lizards will not be affected.
Answer:
Option A, Key stone
Explanation:
A keystone species plays a major role in an ecosystem as it is the species whose presence effects all other species in the ecosystem .In general a keystone species is always a dominant predator that feed on prey population. If it is removed, the prey population will explode and the population diversity will reduce. For example - bison, prairie dog etc.
Hence, option A is correct
Answer:
Pedigree.
Explanation:
Pedigree analysis may be defined as the the method to determnine the family history of a particular trait. The pedigree is important to determine the disease and its inheritance pattern.
The pedigree allows the trace of the inheritance of a particular trait over several generations. The pedigree analysis determines the individual as a carrier of the trait.
Thus, the correct answer is option (B).
