The way I do it is suddenly, in the same sort of way that magicians try to pull a table cloth off a table when there's things on the table cloth.The sudden approach acts as an impulse of force and starts to accelerate the roll. But, the piece (assuming it has perforations) is off the roll before the roll can move, due to inertia. Then the roll will acclerate, move, slow down and stop. However, in accelerating, the roll will unravel. The bigger the impulse the more it will unravel.+++++++++++++++++++++++++++++++++++++++If on the other hand, the piece of paper is held firmly, and the roll is pulled, then the impulse is presumably given to the paper and the hand whose inertia is a lot more than that of the roll. So, I think I'd actually go for choice c)+++++++++++++++++++++++++++++++++++++This assumes that the roll is free to rotate.I think that a similar idea is behind the design and use of a "ballistic galvanometer". The charge is passed through the galvanometer quickly, as a current pulse. Then the needle starts to deflect, and the deflection is arranged to depend on the total charge that has passed through in the time of the current pulse.
Answer:
The balanced equation is 3NaBr+1H3PO4 ----> 1Na3PO4 + 3HBr
This is a double replacement because you are switching both the Na and the Hydrogen.
Explanation:
Answer : A. It decreases and then increases.
Explanation : Troposphere is the lowermost layer of atmosphere.
Stratosphere is next layer up to the troposphere. As the jet descends from stratosphere towards the troposphere, the temperature initially decreases and then at troposphere is roughly constant and then steadily increases.
So, option (A) is correct.
Answer:
= 287kW
Explanation:
Knowing the enthalpy data, we have to
So,
Here,
m=mass flow rate
h= Enthalpy of refrigerant at the compressor
Replacing
= 1.2 × 239.16
= 287kW
