28. A student notices that when a weight is hung on a spring, the spring stretches. She decides to conduct an experiment to determine the relationship between the amount of weight placed on a spring and the distance the spring stretches. She has five different weights: 25 9,50 9.75 9. 100 9, and 125 g. She selects a weight, hangs it on the spring, and
measures how far the spring stretches
What is the independent variable in this experiment?
length of unst etched spring
distance the spring stretches
weight hung from the spring
O temperature of the spring

C). weight hung from the spring

Explanation:

An Independent variable is characterized as the variable that is controlled or manipulated by the experimenter in order to observe its change on the dependent variable.

In the given experiment, 'weight hung from the spring' is the independent variable as it is manipulated by the researcher in order to witness its impact on the dependent variable(how the spring stretches). It is the cause that causes an effect on the dependent variable. Any change in the former directly affects the latter. Thus, option C is the correct answer.

explanation: look here

d₁ = displacement of tern from arctic to antarctic = 11000 miles

d₂ = displacement of tern from antarctic to arctic =   - 11000 miles

d = total displacement for the journey

total displacement for the journey is given as

d = d₁ + d₂

d = 11000 + (-11000)

d = 0 miles

t₁ = time of travel from arctic to antarctic = 3 months = 3 x 30 days = 90 days

t₂ = time of travel from antarctic to arctic = 3 months = 3 x 30 days = 90 days

t = total time of travel

total time of travel is given as

t = t₁ + t₂

t = 90 + 90

t = 180 days

average velocity is given as

average velocity = total displacement/ total time

v = d/t

v = 0/180

v = 0 miles/day