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:

Explanation:
Assuming the we have to find ratio maximum forces on the mass in each case
we know that in a spring mass system
F= Kx
K= spring constant
x= spring displacement
Case 1:

case 2:

therefore, 

The final velocity before takeoff is 104.96 m / s.
<u>Explanation:</u>
The last velocity of a given object over some time defines the final velocity. The final velocity of the object is given by the product of acceleration and time and adding this product to the initial velocity.
To calculate the final velocity,
V = u + at
where v represents the final velocity,
u represents the initial velocity,
a represents the acceleration
t represents the time taken.

v = 104.96 m / s.
Answer:
if the speed of the object triples the kinetic energy becomes nine times the initial kinetic energy. If the speed of an object changes by a factor k, the change in the kinetic energy is of a factor k^2.
Explanation:
Answer: 0.53m
Explanation:
According to the equation of motion v²= v₀²+2as
Since the body is launched upward, the final velocity at the maximum height will be "zero" since the body will momentarily be at rest at the maximum height i.e v = 0
Initial velocity given (v₀) = 3.25 m/s
The body is also under the influence of gravity but the acceleration due to gravity will be negative being an upward force (a = -g) and the distance (s) will serve as our maximum height (h)
The equation of motion will.now become
V = v₀² -2gh
Where v = 0 v₀ = 3.25m/s g = 10m/s h = ?
0 = 3.25² - 2(10)h
0 = 10.56 - 20h
-10.56 = -20h
h = 10.56/20
h = 0.53m
Therefore, the maximum height, h (in meters), above the launch point that the basketball will achieve is 0.53m