You are leaving for a party at your cousin’s house in a city that is 150 km away. You will travel at an average rate of 50 km/hr
2 answers:
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Answer:
8100W
Explanation:
Let g = 10m/s2
As water is falling from 60m high, its potential energy from 60m high would convert to power. So the rate of change in potential energy is
or 9000W
Since 10% of this is lost to friction, we take the remaining 90 %
P = 9000*90% = 8100 W
Answer:
D.None of these
Explanation:
The derivation of acceleration formula:
Let us call the 5kg mass and the 4kg mass
. If the tension in the string is
then for the mass
(1). <em>(the negative sign on the right side indicates that acceleration is downwards)</em>
And for the mass
(2). <em> (the acceleration is upwards, hence the positive sign)</em>
Solving for in the 2nd equation we get:
,
and putting this into the 1st equation we get:
Back to the question:
Using the formula for the acceleration we find
which is the acceleration that none of the given choices offer. Also, the acceleration of the two blocks is the same, because if it weren't, the difference in the instantaneous velocities of the objects would cause the string to break. Therefore, these two reasons make us decide that none of the choices are correct.