Answer:
C. Fill two identical pots with equal volumes of salt water and tap water and use a stopwatch to determine the time it takes each pot to boil.
Explanation:
<u>A) is incorrect</u> because Peter should have the same testing environment for both of his experiments.
He should choose the same method of boiling the salt water and tap water because the stovetop and the microwave could also affect the results and make them unreliable.
<u>B) is incorrect</u> because Peter should not estimate the time it takes the salt water and tap water to boil.
Peter should measure and record the amount of time that it takes these substances to boil in order to have an accurate, valid experimental thesis.
<u>C) is correct</u> because Peter uses the same volume of salt water and tap water, fills them into two identical pots, and uses a stopwatch to determine the amount of time it takes each pot to boil.
The stopwatch makes the experiment more valid and accurate compared to the previous methods, and the identical pots and amounts of water help this experiment become even more precise.
<u>D) is incorrect</u> because the variables in the experiment are not controlled amounts and will therefore produce an inaccurate and invalid experiment.
Answer:
0.027648 kgm²
Explanation:
M = Mass of disc = 1.2 kg
r = Radius of disc = 0.16 m
m = Mass of rod = 0.16 kg
R = Rod distance = 0.16 m
Moment of inertia of disk is given by

Moment of inertia of the three rods

The total moment of inertia is given by

The moment of inertia of the stool with respect to an axis that is perpendicular to the plane of the disk at its center is 0.027648 kgm²
Answer:
approximately 5.8 seconds
Explanation:
if you where to time how fast a rock would fall 12 meters it would approximately be 5.8 seconds
Answer:
1920watts
Explanation:
P=IV
P = 16 x 120 = 1920 watts
The correct answer is going to be <span>C, because in the nucleus of an atom there are protons and electrons; which can't move, and are surrounded by electrons on the electrical cloud</span>