Hannah conducts an investigation to determine if adding fertilizer to the soil helps tomato plants grow taller. She puts 20 tomato plants in individual pots and adds an equal amount of soil to each pot. All 20 plants are the same height at the beginning of the investigation. She adds the same amount of fertilizer to the soil of 10 pots. Hannah measures the height of each plant once a day for 15 days. The presence of fertilizer in the soil is the . The height of the tomato plants is the . The pots without fertilizer are the .

1. independent variable

2. dependent variable

3. control group

Step-by-step explanation:

Independent variables are the factors in the experiment that are being modified to discover some sort of result.

Dependent variables are those that change because of the independent variable; they're also the ones that are measured in the experiment.

The control group is a group that undergoes the same exact procedure as the experimental group(s) do, but without the independent variable; it is to make sure that the different results aren't due to environmental factors.

Here, because Hannah is changing the amount of fertilizer in the plants (none or a specific amount), the presence of fertilizer is the independent variable. Since the heights of the plants will likely change due to the presence of fertilizer, height is the dependent variable. And, finally, the pots without fertilizer undergo the same procedure but without the independent variable, or the fertilizer, so it's the control group.

Hope this helps!

The presence of fertilizer in the soil is the independent variable

The height of the tomato plants is the dependent variable

The pots without fertilizer form the control group

Step-by-step explanation:

She has divided the pots into 2 groups of 10 each:

1) experimental group

2) control group

She can decide the amount of fertiliser so that's an independent variable

What's she's observing are the heights which she can't control so heights is the dependent variable

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.