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:
a = Δv/t = (vf - vi)/t = (0 - 5)/4 = -1.25 m/s²
Explanation:
You may or may not need the negative sign, depending on how the question designer was thinking about the problem.
To solve this problem we will apply the concepts related to Newton's second law that relates force as the product between acceleration and mass. From there, we will get the acceleration. Finally, through the cinematic equations of motion we will find the time required by the object.
If the Force (F) is 42N on an object of mass (m) of 83000kg we have that the acceleration would be by Newton's second law.
Replacing,
The total speed change
we have that the value is 0.71m/s
If we know that acceleration is the change of speed in a fraction of time,
We have that,
Therefore the Rocket should be fired around to 1403.16s
Answer:
1.Gravity is an invisible force that pulls objects toward each other
2.The suns gravity pulls the planet towards the sun which changes the straight line of direction into a curve
That keeps the planet moving in an orbit around the sun
hope it helped:)
