Question

name: libby
for each item below, specify the independent and dependent variables, as well as constants.

1. a study was done to find if different tire treads affect the braking distance of a car

i: ____________ d: __________ c: ____________

1. the time it takes to run a mile depends on the person’s running speed

i: ____________ d: __________ c: ____________

1. the height of bean plants depends on the amount of water they receive.

i: ____________ d: __________ c: ____________

1. the higher the temperature of the air in the oven, the faster a cake will bake.

i: ____________ d: __________ c: ____________

1. lemon trees receiving the most water produced the most lemons.

i: ____________ d: __________ c: ____________

1. an investigation found that more bushels of potatoes were produced when the soil was fertilized more.

i: ____________ d: __________ c: ____________

1. students measured the temperature of the water at different depths in lake skywalker and found that the temperature varied.

i: ____________ d: __________ c: ____________

1. the amount of pollution produced by cars was measured for cars using gasoline containing different amounts of lead.

i: ____________ d: __________ c: ____________

1. four groups of rats are first massed and then fed identical diets except for the amount of vitamin a they receive. each group gets a different amount. after 3 weeks on the diet, the rats’ masses are measured again to see if there has been a decrease

i: ____________ d: __________ c: ____________

Explanation:

1.

• Independent variable (I): What is manipulated, here tire treads (different types).
• Dependent variable (D): What is measured, braking distance (affected by treads).
• Constants (C): Factors kept same, like car model, road conditions, speed before braking.

• I: Running speed (what’s changed to affect time).
• D: Time to run a mile (depends on speed).
• C: Person’s fitness, mile course, weather (kept constant).

• I: Amount of water (manipulated to affect height).
• D: Height of bean plants (depends on water).
• C: Type of bean, soil, sunlight (kept same).

Answer:

I: Tire treads
D: Braking distance of a car
C: Car model, road conditions, initial speed (etc.)

2.