Answer:
725.2 N
Explanation:
Since it is not stated the scale, the person or both accelerated or experience weightlessness, the net force acting on the bathroom scale is the weight of the person acting downward as the person stands on the scale .
Weight = mass of a body × acceleration due to gravity
= 74 kg × 9.8 m/s²
= 725.2 N
The magnitude of work done by the gas is 279 J and the sign is negative so W = -279 J as work is done by the system.
<u>Explanation:</u>
According to first law of thermodynamics, the change in internal energy of the system is equal to the sum of the heat energy added or released from the system with the work done on or by the system. If the heat energy is added to the system to perform a certain work, then the heat energy is taken as positive, while it will be negative when the heat energy is released from the system.
Similarly, in this case, the heat energy of 597 J is added to the system. So the heat energy will be positive, while the gas expansion occurs means work is done by the system.
ΔU = Q+W
Since ΔU is the change in internal energy which is given as 318 J and the heat energy added to the system is Q = 597 J.
Then the work done by the gas = ΔU - Q = 318 J - 597 J = - 279 J.
As the work is done by the system, so it will be denoted in negative sign and the magnitude of work done by the gas is 279 J.
Transmission electron microscope
Answer and Explanation:
NOTE: Magnetism means the magnetic property of a material that causes it to create a magnetic field, hence getting it attracted to a magnet.
EXPERIMENTAL PROCEDURE
1. Use a tape to attach a permanent magnet to the end of a ruler so that the magnet is facing away from the ruler. Don't cover the magnetic surface with the tape. ( Leave the magnet in its decorative casing.)
2. Place your metal objects in a row, and make predictions of which one of them will be attracted to the magnet and which will not.
3. Hold the magnet over each metals, and record which metals are attracted to the magnet. Go back over the
objects that were not affected by the magnet at least one more time to be sure you didn't miss any.
In this experiment, the independent variable is the magnetism of the magnet used. This is the independent variable because it remained unchanged and unaffected by the metals' magnetic properties all through the experiment.
While the dependent variable is the magnetism of the metals used. This is so because the magnetism of these metals varied and also because it is what is been measured in the experiment. Some were attracted to the magnet from very close range while others were attracted even at some centimeters away from the magnet which indicates that those metals have strong metallic properties.
