A family made the observation that more expensive brands of popcorn seem to produce Discovery Education
more popped kernels than cheaper brands of popcorn. In order to test this hypothesis,
the family conducted an experiment in which they followed the procedures below:
•
The family bought 2 differing brands of popcorn to test: Wilbur Bockenreder Popcorn
and PopWhisper.
•
They measured 1 cup of kernels and popped : bowls of each type of popcorn. They
ensured they popped the popcorn for the same amount of time, used the same wattage
microwave, and did not have any other ingredients added to the kernels (butter, etc).
They counted and recorded the number of unpopped kernels in each of the 10 bowls.
As they analyzed the data collected, they were able to conclude that their initial
hypothesis was supported.
They formed the conclusion that the more expensive brand of popcorn popped more
kernels than the cheaper brand of popcorn.
From this experiment, let's answer some questils.
Was this controlled experiment?
no or yes

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y

the doppler effect is used by weather forecasters to measure 

moving clouds

96.77 amp

explanation:

rl = 250/100 = 2.5 ohms.

egl = 250 + (100 × 0.1) + 2 = 262 v.

at 700 r.p.m., eg2 = 262 × 700/1000 = 183.4 v.

if ia is the new current, then eg2 - 2 - (ia × 0.1) = 2.5 ia

which means this will give ia = 96.77 amp.