The answer you are looking for would be C. "She asks her lab partner which base he thinks is hardest to study"
This is the correct option out of the other choices.
A. She uses a acid-base indicator to measure the pH of four different solutions
B. She mixes two solutions and measures their pH before and after
C. She asks her lab partner which base he thinks is the hardest to study
D. She measures the temperature of a solution before and after adding H2SO4
Answer:
(a) 5.7 s
(b) 39 m/s
Explanation:
(a) u = 18 m/s
At the maximum height, the final velocity of ball is zero. lte teh time taken by the ball to go from 50 m height to maximum height is t.
use first equation of motion.
v = u + g t
0 = 18 - 10 x t
t = 1.8 s
Let the maximum height attained by the ball when it thrown from 50 m height is h'.
Use third equation of motion
v^2 = u^2 + 2 g h'
0 = 18^2 - 2 x 10 x h'
h' = 16.2 m
Total height from the ground H = h + h' = 50 + 16.2 = 76.2 m
Let t' be the time taken by the ball to hit the ground as it falls from maximum height.
use third equation of motion
H = ut + 1/2 x g t'^2
76.2 = 0 + 1/2 x 10 x t'^2
t' = 3.9 s
Total time taken by the ball to hit the ground = T = t + t' = 1.8 + 3.9 = 5.7 s
(b) Let v be the velocity with which the ball strikes the ground.
v^2 = u^2 + 2 g H
v^2 = 0 + 2 x 10 x 76.2
v = 39 m/s
The type of relationship between atmospheric density and altitude is therefore inverse relationship. This means an increase in either will decrease the other factor. Density is mass per unit volume, it is difficult to calculate with only altitude 1,291 kilometers given. Else, we could also use temperature and pressure to solve density but they are not provided.
<span>sometimes you can see yourself as well, due to refraction and reflection
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