Answer:
When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.
Explanation:
A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.
Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.
When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma
When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma
However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg
When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0
Answer:
Specific heat of water is 4.186 J/g/C. The heat required to raise the temperature by
is
Here is mass of water being heated, specific heat of water and change in temperature.
Here .
Heat energy required is
Explanation:
Answer:
B) shrinks
Explanation:
The magnetic force is a force exerted between two magnets, or two magnetic materials, or also on an electric charge moving in a magnetic field.
If we talk about magnetic material, the magnetic field they generates can be represented using a dipole: essentially, they have a north pole (where the lines of the field go out) and a south pole (where the lines of the field go in).
Also, the lines spread apart as we move away from the magnet itself. This means that the strength of the field (and so, the intensity of the force) decreases as we move away from the magnet.
Using this description, we can now understand that when we move the paper clip further from the magnet, the force exerted on the clip decreases, as the magnetic field becomes weaker. So, the correct answer is B.
I think the correct answer is the second option. A circuit describes a closed conducting loop through which an electrical current can flow. It is a path that an electrical current could flow. A circuit could be a closed one or an open circuit. A closed circuit would be a circuit where the current could flow continuously. An open circuit would be a type of circuit where the flow current would only go once and stopped at a particular point since the current has nowhere to go. For a circuit to work, an electric supply should be available to supply the electric current.
A real cubic expansivity is an increase in the volume of a liquid per unit volume per degree rise in temperature when heated in an inexpansible vessel.
