Independent variable, dependent variable, and constant

Independent variable

Cause

Dependent variable

Effect

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

IV: different tire trends.

DV: braking distance.

Constant: the car

The time it takes to run a mile depends on the person's running speed.

IV: running speed

DV: time it takes

Constant: mile

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

IV: amount of water

DV: height of the bean plant

Constant: plant

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

IV: temperature of the air

DV: time it takes cake to bake

Constant: cake

Lemon trees receiving the most water produced the most lemons.

IV: receiving the most water

DV: producted the most lemons

Constant: lemon trees

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

IV: soil was fertilized more

DV: more bushels of potatoes are produced

Constant: bushels of potatoes

Students measured the temperature of the water at different depths in Lake Skywalker and found that the temperature varied.

IV: depths of water

DV: temperature

Constant: depths

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

IV: different amounts of lead

DV: population increases

Constant: type of car

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.

IV: amount of vitamin A

DV: mass

Constant: diet