Answer:
This question is incomplete as it lacks options, the options are:
Which change would be the most effective way to improve the validity of this experiment?
A) Increase the number of goldfish in each tank.
B) Increase the daily amount of food for each tank.
C) Create another group that is fed regular fish food.
D) Increase the number of tanks in each treatment group.
The answer is C
Explanation:
According to this question, an experiment is conducted by Trey to determine which fish food causes the most goldfish activity over a period of two weeks. In this experiment, the independent variable is the FISH FOOD which are; Swift Salmon food and Fast Flounder food. Other variables such as type of gold fish, amount of fish food, amount & type of water etc.
One of the ways to improve an experiment, which is lacking in this case is to have a CONTROL GROUP. Based on the fish foods used for each group, it is obvious that all groups in this experiment are experimental. Hence, creating another group that is fed regular fish food will serve as the CONTROL GROUP in order to compare with the experimental groups. This will improve the validity of the experiment.
Net force acting on the car is 3 x 10^3 Newtons:
Suspension, saltation, and surface creep are the three types of soil movement which occur during wind erosion. While soil can be blown away at virtually any height, the majority (over 93%) of soil movement takes place at or below one meter.
Suspension occurs when very fine dirt and dust particles are lifted into the wind. They can be thrown into the air through impact with other particles or by the wind itself. Once in the atmosphere, these particles can be carried very high and be transported over extremely long distances. Soil moved by suspension is the most spectacular and easiest to recognize of the three forms of movement.
Saltation - The major fraction of soil moved by the wind is through the process of saltation. In saltation, fine soil particles are lifted into the air by the wind and drift horizontally across the surface increasing in velocity as they go. Soil particles moved in this process of saltation can cause severe damage to the soil surface and vegetation. They travel approximately four times longer in distance than in height. When they strike the surface again they either rebound back into the air or knock other particles into the air.
Creep - The large particles which are too heavy to be lifted into the air are moved through a process called surface creep. In this process, the particles are rolled across the surface after coming into contact with the soil particles in saltation.
Hope this helps
Tried to be detailed ;)
H = height of the pole = ?
BC = ED = height of the transit = 4 ft
CD = BE = distance moved away from the base of the pole = 140 ft
Consider the ΔABE
tan44 = AE/BE
tan44 = h/140
h = 140 tan44
h = 135.2 ft
H = height of pole = AE + ED = h + ED = 135.2 + 4
H = 139.2 ft
Answer: set of rules based on standards and guidelines.