Answer: D
Experiment 1 has a confounding variable related to the mass of the rockets. Any variation in mass may cause a discrepancy in the distance traveled.
This is the answer to the question because:
- Both experiments do have a confounding variable.
- Experiment 1 doesn't have to stay constant.
- A double-blind experiment will not do anything to the placebo.
- High blood pressure people will not make the results confusing.
The answer has to be the option D. Hope this helps you!
In order to calculate the thermal energy, first let's calculate the power, using the formula:

For a voltage V = 9 Volts and a resistance R = 50 ohms, we have:

Now, multiplying the power by the time (in seconds), we can find the energy:

In scientific notation, we have an energy of 7.3 * 10^2 J, therefore the correct option is the fourth one.
Answer:

direction is Horizontal
Explanation:
As we know that the string is horizontal here
so the tension force in the string is due to electrostatic force on it
now we will have

so here the force is tension force on it


now we have


direction is Horizontal
Answer:
Average accelation = -4V
Explanation:

V=0 m/s (because the frog stopped)
V0 = V (average velocity)
t= 0,25 s
So;
