Answer:
D. Validity group
Explanation:
A validity group is not necessarily a component of a normal experiment.
A normal experiment is made up of the dependent variables, independent variables, and most times the control group.
- The dependent variable is one that relies on the outcome of the effect produced from the experimental design
- The independent variable is the one that causes a desired effect under the study.
- The control group is a group that does not receive any treatment nor attenuation of the conditions.
Answer:
Option B. 32 g
Explanation:
From the question given above, the following data were obtained:
Original amount (N₀) = 128 g
Half-life (t½) = 2.25 billion years
Number of half-lives (n) = 2
Amount remaining (N) =?
The amount of 128 gram of Radium-226 that will remain after 2 half-lives has elapsed can be obtained as followb
N = 1/2ⁿ × N₀
N = 1/2² × 128
N = 1/4 × 128
N = 0.25 × 128
N = 32 g
Therefore, 32g of the sample will remain.
Answer:
t = 4 s
Explanation:
As we know that the particle A starts from Rest with constant acceleration
So the distance moved by the particle in given time "t"



Now we know that B moves with constant speed so in the same time B will move to another distance

now we know that B is already 349 cm down the track
so if A and B will meet after time "t"
then in that case


on solving above kinematics equation we have

b. describes it best because a form of molten cools down and makes igneous rock. Good luck! Please mark me brainliest!
Answer:
The value is 
Explanation:
From the question we are told that
The number of turns is N = 1000
The length is L = 50 cm = 0.50 m
The radius is r = 2.0 cm = 0.02 m
The current is I = 18.0 A
Generally the magnetic field is mathematically represented as

Here
is the permeability of free space with value

So

=> 