A type of matter made up of a combination of elements is called a compound. for example table salt, is made up of two elements that by themselves are lethal but chemically combined cancel each other out there for becoming edible.
Answer:
0.02
Explanation:
coefficient of kinetic friction = μ
force of friction = Ff
Normal Force = FN, but
FN = -W
Ff = -μFN
so μ = Ff/FN
= 4N/200N
= 0.02.
Answer:
The hypothesis may or may not be true and needs to be tested. It might be the answer to the problem. Hence, it must be tested thoroughly. When these predictions are tested again and again in independent scientific experiments and gets verified, the hypothesis is converted into a scientific theory.
Answer:
A) d = 11.8m
B) d = 4.293 m
Explanation:
A) We are told that the angle of incidence;θ_i = 70°.
Now, if refraction doesn't occur, the angle of the light continues to be 70° in the water relative to the normal. Thus;
tan 70° = d/4.3m
Where d is the distance from point B at which the laser beam would strike the lakebottom.
So,d = 4.3*tan70
d = 11.8m
B) Since the light is moving from air (n1=1.00) to water (n2=1.33), we can use Snell's law to find the angle of refraction(θ_r)
So,
n1*sinθ_i = n2*sinθ_r
Thus; sinθ_r = (n1*sinθ_i)/n2
sinθ_r = (1 * sin70)/1.33
sinθ_r = 0.7065
θ_r = sin^(-1)0.7065
θ_r = 44.95°
Thus; xonsidering refraction, distance from point B at which the laser beam strikes the lake-bottom is calculated from;
d = 4.3 tan44.95
d = 4.293 m
Answer:
The correct answer is "22.27 hours".
Explanation:
Given that:
Radioactive isotope activity,
= 490,000 Bq
Activity,
= 110,000 Bq
Time,
= 48 hours
As we know,
⇒ 
or,
⇒ 
By taking "ln", we get
⇒ 
By substituting the values, we get
⇒ 
⇒ 
As,
⇒ 
then,
⇒ 
⇒ 
