Positive - Friction allows us to create heat in a desperate situation, like being lost in the woods. If we didn't have friction, we would probably freeze to death.
Negative - Friction can also cause unwanted fires, such as forest fires. If friction didn't exist, we wouldn't have these.
Answer:
A hypothesis for the period of a pendulum is:
"The period of the pendulum varies with its length"
Explanation:
A hypothesis for the period of a pendulum is:
"The period of the pendulum varies with its length"
To test this hypothesis we can carry out a measurement of a simple pendulum keeping the angle fixed, in general the angle used is about 5º since when placing this value in radiand and the sine of this angle they differ little <5%. therefore measured the time of some oscillations, for example about 10 oscillations, changing the length of the pendulum to test the hypothesis.
If the hypothesis and the model used is correct, the relationship to be tested is
T² =(4π² /g) L
by making a graph of the period squared against the length if obtaining, os a line, the hypothesis is tested.
The efficiency of steam engine is 26.66 %.
<h3>What is Efficiency?</h3>
The efficiency is defined as the work done by the engine divided by the heat supplied.
Work done is the difference between the heat supplied and heat rejected.
So, efficiency η = (Qs -Qr) / Qs
Given is the heat supplied Qs = 225 Joules and heat rejected Qr =285 . then the work done is
W = 225 -225 = - 60 Joules
Efficiency η = 60/225 x 100%
η = 26.66 %
Thus, the efficiency of the steam engine is 26.66 %.
Learn more about efficiency.
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Answer:
Explanation:
They need a galvanic difference. Or saying that less technically, they need to have different electron attraction, so that one can collect electrons (oxidation/reduction) and flow current from the other. :)
Answer:
total distance is 147 km
and john displacement is = 89 km
Explanation:
given data
mile marker = 252 km
reach = 134 km
retrace path = 163 km
to find out
resultant displacement
solution
we know here john travel from 252 km mark
and he reach at 134 km
so he travel distance part1 = 252 - 134
distance d1 = 252 - 134 = 118 km ..............1
and
then he start travel from 134 km mark upto 163 km mark
so distance travel in part 2 is
distance d2 = 163 - 134 = 29 km ....................2
so total distance is 118 + 29 = 147 km
and john displacement is = 252 - 163 = 89 km
