Answer:
The heat causes the molecules on rubbing surfaces to move faster and have more energy.
Dipper effect of an oncoming train get louder as it approaches and sound diminishes as it goes away sound traveling
<u>Question:</u>
You are working on an experiment involving a very strong permanent magnet, and your data suggests that your magnet's field suddenly decreased during some interval in time. Such a decrease could have been caused by the magnet
A. Having overheated substantially
B. Being hit hard
C. Both A and B
D. Being grounded out
<h3><u>Answer:</u></h3>
A decrease in magnetic field of the permanent magnet have been caused by the magnet having overheated substantially or sharp impacts by being hit hard.
Option c
<h3><u>Explanation: </u></h3>
Permanent magnets are ferromagnetic materials with its magnetic domains aligned and grouped together in the same direction. These atomic domains maintain their directionality and hence a permanent magnet provides persistently strong magnetic fields without quick weakening. Some factors may lead to demagnetization or else a consistent reduction in magnetic strength.
Overheating a magnetic material realigns the magnetic domain regions and affects its directionality. When it reaches to a temperature defined as Curie temperature, varying with each material; the substance is no more a magnet due to complete randomness in the domain structure. As the temperature decreases and approaches the room temperature, magnetic field appears but is less in strength. Sudden impacts due to hitting may lead to random realignment of magnetic domains and thus decrease its magnetic strength.
Answer: Zero.
Explanation:
By the first Newton's law, we know that:
every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
Now, we know that the car is moving with constant speed, then there is no net force acting on the car, which means that the car is already in equilibrium.
Then if we add one force to the situation, the car will not be anymore in equilibrium.
The correct option is zero.
